datetime
â Basic date and time types¶
Source code: Lib/datetime.py
The datetime
module supplies classes for manipulating dates and times.
While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation.
See also
calendar
General calendar related functions.
time
Time access and conversions.
zoneinfo
Concrete time zones representing the IANA time zone database.
Third-party library with expanded time zone and parsing support.
Third-party library that introduces distinct static types to e.g. allow static type checkers to differentiate between naive and aware datetimes.
Date and time objects may be categorized as âawareâ or ânaiveâ depending on whether or not they include time zone information.
With sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, an aware object can locate itself relative to other aware objects. An aware object represents a specific moment in time that is not open to interpretation. [1]
A naive object does not contain enough information to unambiguously locate itself relative to other date/time objects. Whether a naive object represents Coordinated Universal Time (UTC), local time, or time in some other time zone is purely up to the program, just like it is up to the program whether a particular number represents metres, miles, or mass. Naive objects are easy to understand and to work with, at the cost of ignoring some aspects of reality.
For applications requiring aware objects, datetime
and time
objects have an optional time zone information attribute, tzinfo
, that can be set to an instance of a subclass of the abstract tzinfo
class. These tzinfo
objects capture information about the offset from UTC time, the time zone name, and whether daylight saving time is in effect.
Only one concrete tzinfo
class, the timezone
class, is supplied by the datetime
module. The timezone
class can represent simple time zones with fixed offsets from UTC, such as UTC itself or North American EST and EDT time zones. Supporting time zones at deeper levels of detail is up to the application. The rules for time adjustment across the world are more political than rational, change frequently, and there is no standard suitable for every application aside from UTC.
The datetime
module exports the following constants:
Alias for the UTC time zone singleton datetime.timezone.utc
.
Added in version 3.11.
An idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes: year
, month
, and day
.
An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. (There is no notion of âleap secondsâ here.) Attributes: hour
, minute
, second
, microsecond
, and tzinfo
.
A combination of a date and a time. Attributes: year
, month
, day
, hour
, minute
, second
, microsecond
, and tzinfo
.
A duration expressing the difference between two datetime
or date
instances to microsecond resolution.
An abstract base class for time zone information objects. These are used by the datetime
and time
classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).
A class that implements the tzinfo
abstract base class as a fixed offset from the UTC.
Added in version 3.2.
Objects of these types are immutable.
Subclass relationships:
object timedelta tzinfo timezone time date datetimeCommon Properties¶
The date
, datetime
, time
, and timezone
types share these common features:
Objects of these types are immutable.
Objects of these types are hashable, meaning that they can be used as dictionary keys.
Objects of these types support efficient pickling via the pickle
module.
Objects of the date
type are always naive.
An object of type time
or datetime
may be aware or naive.
A datetime
object d
is aware if both of the following hold:
d.tzinfo
is not None
d.tzinfo.utcoffset(d)
does not return None
Otherwise, d
is naive.
A time
object t
is aware if both of the following hold:
t.tzinfo
is not None
t.tzinfo.utcoffset(None)
does not return None
.
Otherwise, t
is naive.
The distinction between aware and naive doesnât apply to timedelta
objects.
timedelta
Objects¶
A timedelta
object represents a duration, the difference between two datetime
or date
instances.
All arguments are optional and default to 0. Arguments may be integers or floats, and may be positive or negative.
Only days, seconds and microseconds are stored internally. Arguments are converted to those units:
A millisecond is converted to 1000 microseconds.
A minute is converted to 60 seconds.
An hour is converted to 3600 seconds.
A week is converted to 7 days.
and days, seconds and microseconds are then normalized so that the representation is unique, with
0 <= microseconds < 1000000
0 <= seconds < 3600*24
(the number of seconds in one day)
-999999999 <= days <= 999999999
The following example illustrates how any arguments besides days, seconds and microseconds are âmergedâ and normalized into those three resulting attributes:
>>> from datetime import timedelta >>> delta = timedelta( ... days=50, ... seconds=27, ... microseconds=10, ... milliseconds=29000, ... minutes=5, ... hours=8, ... weeks=2 ... ) >>> # Only days, seconds, and microseconds remain >>> delta datetime.timedelta(days=64, seconds=29156, microseconds=10)
If any argument is a float and there are fractional microseconds, the fractional microseconds left over from all arguments are combined and their sum is rounded to the nearest microsecond using round-half-to-even tiebreaker. If no argument is a float, the conversion and normalization processes are exact (no information is lost).
If the normalized value of days lies outside the indicated range, OverflowError
is raised.
Note that normalization of negative values may be surprising at first. For example:
>>> from datetime import timedelta >>> d = timedelta(microseconds=-1) >>> (d.days, d.seconds, d.microseconds) (-1, 86399, 999999)
Since the string representation of timedelta
objects can be confusing, use the following recipe to produce a more readable format:
>>> def pretty_timedelta(td): ... if td.days >= 0: ... return str(td) ... return f'-({-td!s})' ... >>> d = timedelta(hours=-1) >>> str(d) # not human-friendly '-1 day, 23:00:00' >>> pretty_timedelta(d) '-(1:00:00)'
Class attributes:
The most negative timedelta
object, timedelta(-999999999)
.
The most positive timedelta
object, timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999)
.
The smallest possible difference between non-equal timedelta
objects, timedelta(microseconds=1)
.
Note that, because of normalization, timedelta.max
is greater than -timedelta.min
. -timedelta.max
is not representable as a timedelta
object.
Instance attributes (read-only):
Between -999,999,999 and 999,999,999 inclusive.
Between 0 and 86,399 inclusive.
Caution
It is a somewhat common bug for code to unintentionally use this attribute when it is actually intended to get a total_seconds()
value instead:
>>> from datetime import timedelta >>> duration = timedelta(seconds=11235813) >>> duration.days, duration.seconds (130, 3813) >>> duration.total_seconds() 11235813.0
Between 0 and 999,999 inclusive.
Supported operations:
Operation
Result
t1 = t2 + t3
Sum of t2
and t3
. Afterwards t1 - t2 == t3
and t1 - t3 == t2
are true. (1)
t1 = t2 - t3
Difference of t2
and t3
. Afterwards t1 == t2 - t3
and t2 == t1 + t3
are true. (1)(6)
t1 = t2 * i or t1 = i * t2
Delta multiplied by an integer. Afterwards t1 // i == t2
is true, provided i != 0
.
In general, t1 * i == t1 * (i-1) + t1
is true. (1)
t1 = t2 * f or t1 = f * t2
Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f = t2 / t3
Division (3) of overall duration t2
by interval unit t3
. Returns a float
object.
t1 = t2 / f or t1 = t2 / i
Delta divided by a float or an int. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
t1 = t2 // i
or t1 = t2 // t3
The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1 = t2 % t3
The remainder is computed as a timedelta
object. (3)
q, r = divmod(t1, t2)
Computes the quotient and the remainder: q = t1 // t2
(3) and r = t1 % t2
. q
is an integer and r
is a timedelta
object.
+t1
Returns a timedelta
object with the same value. (2)
-t1
Equivalent to timedelta(-t1.days, -t1.seconds, -t1.microseconds)
, and to t1 * -1
. (1)(4)
abs(t)
Equivalent to +t
when t.days >= 0
, and to -t
when t.days < 0
. (2)
str(t)
Returns a string in the form [D day[s], ][H]H:MM:SS[.UUUUUU]
, where D is negative for negative t
. (5)
repr(t)
Returns a string representation of the timedelta
object as a constructor call with canonical attribute values.
Notes:
This is exact but may overflow.
This is exact and cannot overflow.
Division by zero raises ZeroDivisionError
.
-timedelta.max
is not representable as a timedelta
object.
String representations of timedelta
objects are normalized similarly to their internal representation. This leads to somewhat unusual results for negative timedeltas. For example:
>>> timedelta(hours=-5) datetime.timedelta(days=-1, seconds=68400) >>> print(_) -1 day, 19:00:00
The expression t2 - t3
will always be equal to the expression t2 + (-t3)
except when t3 is equal to timedelta.max
; in that case the former will produce a result while the latter will overflow.
In addition to the operations listed above, timedelta
objects support certain additions and subtractions with date
and datetime
objects (see below).
Changed in version 3.2: Floor division and true division of a timedelta
object by another timedelta
object are now supported, as are remainder operations and the divmod()
function. True division and multiplication of a timedelta
object by a float
object are now supported.
timedelta
objects support equality and order comparisons.
In Boolean contexts, a timedelta
object is considered to be true if and only if it isnât equal to timedelta(0)
.
Instance methods:
Return the total number of seconds contained in the duration. Equivalent to td / timedelta(seconds=1)
. For interval units other than seconds, use the division form directly (e.g. td / timedelta(microseconds=1)
).
Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.
Added in version 3.2.
timedelta
¶
An additional example of normalization:
>>> # Components of another_year add up to exactly 365 days >>> from datetime import timedelta >>> year = timedelta(days=365) >>> another_year = timedelta(weeks=40, days=84, hours=23, ... minutes=50, seconds=600) >>> year == another_year True >>> year.total_seconds() 31536000.0
Examples of timedelta
arithmetic:
>>> from datetime import timedelta >>> year = timedelta(days=365) >>> ten_years = 10 * year >>> ten_years datetime.timedelta(days=3650) >>> ten_years.days // 365 10 >>> nine_years = ten_years - year >>> nine_years datetime.timedelta(days=3285) >>> three_years = nine_years // 3 >>> three_years, three_years.days // 365 (datetime.timedelta(days=1095), 3)
date
Objects¶
A date
object represents a date (year, month and day) in an idealized calendar, the current Gregorian calendar indefinitely extended in both directions.
January 1 of year 1 is called day number 1, January 2 of year 1 is called day number 2, and so on. [2]
All arguments are required. Arguments must be integers, in the following ranges:
MINYEAR <= year <= MAXYEAR
1 <= month <= 12
1 <= day <= number of days in the given month and year
If an argument outside those ranges is given, ValueError
is raised.
Other constructors, all class methods:
Return the current local date.
This is equivalent to date.fromtimestamp(time.time())
.
Return the local date corresponding to the POSIX timestamp, such as is returned by time.time()
.
This may raise OverflowError
, if the timestamp is out of the range of values supported by the platform C localtime()
function, and OSError
on localtime()
failure. Itâs common for this to be restricted to years from 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp()
.
Changed in version 3.3: Raise OverflowError
instead of ValueError
if the timestamp is out of the range of values supported by the platform C localtime()
function. Raise OSError
instead of ValueError
on localtime()
failure.
Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
ValueError
is raised unless 1 <= ordinal <= date.max.toordinal()
. For any date d
, date.fromordinal(d.toordinal()) == d
.
Return a date
corresponding to a date_string given in any valid ISO 8601 format, with the following exceptions:
Reduced precision dates are not currently supported (YYYY-MM
, YYYY
).
Extended date representations are not currently supported (±YYYYYY-MM-DD
).
Ordinal dates are not currently supported (YYYY-OOO
).
Examples:
>>> from datetime import date >>> date.fromisoformat('2019-12-04') datetime.date(2019, 12, 4) >>> date.fromisoformat('20191204') datetime.date(2019, 12, 4) >>> date.fromisoformat('2021-W01-1') datetime.date(2021, 1, 4)
Added in version 3.7.
Changed in version 3.11: Previously, this method only supported the format YYYY-MM-DD
.
Return a date
corresponding to the ISO calendar date specified by year, week and day. This is the inverse of the function date.isocalendar()
.
Added in version 3.8.
Class attributes:
The earliest representable date, date(MINYEAR, 1, 1)
.
The latest representable date, date(MAXYEAR, 12, 31)
.
The smallest possible difference between non-equal date objects, timedelta(days=1)
.
Instance attributes (read-only):
Between 1 and 12 inclusive.
Between 1 and the number of days in the given month of the given year.
Supported operations:
Operation
Result
date2 = date1 + timedelta
date2
will be timedelta.days
days after date1
. (1)
date2 = date1 - timedelta
Computes date2
such that date2 + timedelta == date1
. (2)
timedelta = date1 - date2
(3)
date1 == date2
date1 != date2
Equality comparison. (4)
date1 < date2
date1 > date2
date1 <= date2
date1 >= date2
Order comparison. (5)
Notes:
date2 is moved forward in time if timedelta.days > 0
, or backward if timedelta.days < 0
. Afterward date2 - date1 == timedelta.days
. timedelta.seconds
and timedelta.microseconds
are ignored. OverflowError
is raised if date2.year
would be smaller than MINYEAR
or larger than MAXYEAR
.
timedelta.seconds
and timedelta.microseconds
are ignored.
This is exact, and cannot overflow. timedelta.seconds
and timedelta.microseconds
are 0, and date2 + timedelta == date1
after.
date
objects are equal if they represent the same date.
date
objects that are not also datetime
instances are never equal to datetime
objects, even if they represent the same date.
date1 is considered less than date2 when date1 precedes date2 in time. In other words, date1 < date2
if and only if date1.toordinal() < date2.toordinal()
.
Order comparison between a date
object that is not also a datetime
instance and a datetime
object raises TypeError
.
Changed in version 3.13: Comparison between datetime
object and an instance of the date
subclass that is not a datetime
subclass no longer converts the latter to date
, ignoring the time part and the time zone. The default behavior can be changed by overriding the special comparison methods in subclasses.
In Boolean contexts, all date
objects are considered to be true.
Instance methods:
Return a new date
object with the same values, but with specified parameters updated.
Example:
>>> from datetime import date >>> d = date(2002, 12, 31) >>> d.replace(day=26) datetime.date(2002, 12, 26)
The generic function copy.replace()
also supports date
objects.
Return a time.struct_time
such as returned by time.localtime()
.
The hours, minutes and seconds are 0, and the DST flag is -1.
d.timetuple()
is equivalent to:
time.struct_time((d.year, d.month, d.day, 0, 0, 0, d.weekday(), yday, -1))
where yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1
is the day number within the current year starting with 1 for January 1st.
Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1. For any date
object d
, date.fromordinal(d.toordinal()) == d
.
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. For example, date(2002, 12, 4).weekday() == 2
, a Wednesday. See also isoweekday()
.
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. For example, date(2002, 12, 4).isoweekday() == 3
, a Wednesday. See also weekday()
, isocalendar()
.
Return a named tuple object with three components: year
, week
and weekday
.
The ISO calendar is a widely used variant of the Gregorian calendar. [3]
The ISO year consists of 52 or 53 full weeks, and where a week starts on a Monday and ends on a Sunday. The first week of an ISO year is the first (Gregorian) calendar week of a year containing a Thursday. This is called week number 1, and the ISO year of that Thursday is the same as its Gregorian year.
For example, 2004 begins on a Thursday, so the first week of ISO year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004:
>>> from datetime import date >>> date(2003, 12, 29).isocalendar() datetime.IsoCalendarDate(year=2004, week=1, weekday=1) >>> date(2004, 1, 4).isocalendar() datetime.IsoCalendarDate(year=2004, week=1, weekday=7)
Changed in version 3.9: Result changed from a tuple to a named tuple.
Return a string representing the date in ISO 8601 format, YYYY-MM-DD
:
>>> from datetime import date >>> date(2002, 12, 4).isoformat() '2002-12-04'
For a date d
, str(d)
is equivalent to d.isoformat()
.
Return a string representing the date:
>>> from datetime import date >>> date(2002, 12, 4).ctime() 'Wed Dec 4 00:00:00 2002'
d.ctime()
is equivalent to:
time.ctime(time.mktime(d.timetuple()))
on platforms where the native C ctime()
function (which time.ctime()
invokes, but which date.ctime()
does not invoke) conforms to the C standard.
Return a string representing the date, controlled by an explicit format string. Format codes referring to hours, minutes or seconds will see 0 values. See also strftime() and strptime() Behavior and date.isoformat()
.
Same as date.strftime()
. This makes it possible to specify a format string for a date
object in formatted string literals and when using str.format()
. See also strftime() and strptime() Behavior and date.isoformat()
.
date
¶
Example of counting days to an event:
>>> import time >>> from datetime import date >>> today = date.today() >>> today datetime.date(2007, 12, 5) >>> today == date.fromtimestamp(time.time()) True >>> my_birthday = date(today.year, 6, 24) >>> if my_birthday < today: ... my_birthday = my_birthday.replace(year=today.year + 1) ... >>> my_birthday datetime.date(2008, 6, 24) >>> time_to_birthday = abs(my_birthday - today) >>> time_to_birthday.days 202
More examples of working with date
:
>>> from datetime import date >>> d = date.fromordinal(730920) # 730920th day after 1. 1. 0001 >>> d datetime.date(2002, 3, 11) >>> # Methods related to formatting string output >>> d.isoformat() '2002-03-11' >>> d.strftime("%d/%m/%y") '11/03/02' >>> d.strftime("%A %d. %B %Y") 'Monday 11. March 2002' >>> d.ctime() 'Mon Mar 11 00:00:00 2002' >>> 'The {1} is {0:%d}, the {2} is {0:%B}.'.format(d, "day", "month") 'The day is 11, the month is March.' >>> # Methods for to extracting 'components' under different calendars >>> t = d.timetuple() >>> for i in t: ... print(i) 2002 # year 3 # month 11 # day 0 0 0 0 # weekday (0 = Monday) 70 # 70th day in the year -1 >>> ic = d.isocalendar() >>> for i in ic: ... print(i) 2002 # ISO year 11 # ISO week number 1 # ISO day number ( 1 = Monday ) >>> # A date object is immutable; all operations produce a new object >>> d.replace(year=2005) datetime.date(2005, 3, 11)
datetime
Objects¶
A datetime
object is a single object containing all the information from a date
object and a time
object.
Like a date
object, datetime
assumes the current Gregorian calendar extended in both directions; like a time
object, datetime
assumes there are exactly 3600*24 seconds in every day.
Constructor:
The year, month and day arguments are required. tzinfo may be None
, or an instance of a tzinfo
subclass. The remaining arguments must be integers in the following ranges:
MINYEAR <= year <= MAXYEAR
,
1 <= month <= 12
,
1 <= day <= number of days in the given month and year
,
0 <= hour < 24
,
0 <= minute < 60
,
0 <= second < 60
,
0 <= microsecond < 1000000
,
fold in [0, 1]
.
If an argument outside those ranges is given, ValueError
is raised.
Changed in version 3.6: Added the fold parameter.
Other constructors, all class methods:
Return the current local date and time, with tzinfo
None
.
Equivalent to:
datetime.fromtimestamp(time.time())
See also now()
, fromtimestamp()
.
This method is functionally equivalent to now()
, but without a tz
parameter.
Return the current local date and time.
If optional argument tz is None
or not specified, this is like today()
, but, if possible, supplies more precision than can be gotten from going through a time.time()
timestamp (for example, this may be possible on platforms supplying the C gettimeofday()
function).
If tz is not None
, it must be an instance of a tzinfo
subclass, and the current date and time are converted to tzâs time zone.
This function is preferred over today()
and utcnow()
.
Note
Subsequent calls to datetime.now()
may return the same instant depending on the precision of the underlying clock.
Return the current UTC date and time, with tzinfo
None
.
This is like now()
, but returns the current UTC date and time, as a naive datetime
object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc)
. See also now()
.
Warning
Because naive datetime
objects are treated by many datetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing the current time in UTC is by calling datetime.now(timezone.utc)
.
Deprecated since version 3.12: Use datetime.now()
with UTC
instead.
Return the local date and time corresponding to the POSIX timestamp, such as is returned by time.time()
. If optional argument tz is None
or not specified, the timestamp is converted to the platformâs local date and time, and the returned datetime
object is naive.
If tz is not None
, it must be an instance of a tzinfo
subclass, and the timestamp is converted to tzâs time zone.
fromtimestamp()
may raise OverflowError
, if the timestamp is out of the range of values supported by the platform C localtime()
or gmtime()
functions, and OSError
on localtime()
or gmtime()
failure. Itâs common for this to be restricted to years in 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp()
, and then itâs possible to have two timestamps differing by a second that yield identical datetime
objects. This method is preferred over utcfromtimestamp()
.
Changed in version 3.3: Raise OverflowError
instead of ValueError
if the timestamp is out of the range of values supported by the platform C localtime()
or gmtime()
functions. Raise OSError
instead of ValueError
on localtime()
or gmtime()
failure.
Changed in version 3.6: fromtimestamp()
may return instances with fold
set to 1.
Return the UTC datetime
corresponding to the POSIX timestamp, with tzinfo
None
. (The resulting object is naive.)
This may raise OverflowError
, if the timestamp is out of the range of values supported by the platform C gmtime()
function, and OSError
on gmtime()
failure. Itâs common for this to be restricted to years in 1970 through 2038.
To get an aware datetime
object, call fromtimestamp()
:
datetime.fromtimestamp(timestamp, timezone.utc)
On the POSIX compliant platforms, it is equivalent to the following expression:
datetime(1970, 1, 1, tzinfo=timezone.utc) + timedelta(seconds=timestamp)
except the latter formula always supports the full years range: between MINYEAR
and MAXYEAR
inclusive.
Warning
Because naive datetime
objects are treated by many datetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing a specific timestamp in UTC is by calling datetime.fromtimestamp(timestamp, tz=timezone.utc)
.
Changed in version 3.3: Raise OverflowError
instead of ValueError
if the timestamp is out of the range of values supported by the platform C gmtime()
function. Raise OSError
instead of ValueError
on gmtime()
failure.
Deprecated since version 3.12: Use datetime.fromtimestamp()
with UTC
instead.
Return the datetime
corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError
is raised unless 1 <= ordinal <= datetime.max.toordinal()
. The hour, minute, second and microsecond of the result are all 0, and tzinfo
is None
.
Return a new datetime
object whose date components are equal to the given date
objectâs, and whose time components are equal to the given time
objectâs. If the tzinfo argument is provided, its value is used to set the tzinfo
attribute of the result, otherwise the tzinfo
attribute of the time argument is used. If the date argument is a datetime
object, its time components and tzinfo
attributes are ignored.
For any datetime
object d
, d == datetime.combine(d.date(), d.time(), d.tzinfo)
.
Changed in version 3.6: Added the tzinfo argument.
Return a datetime
corresponding to a date_string in any valid ISO 8601 format, with the following exceptions:
Time zone offsets may have fractional seconds.
The T
separator may be replaced by any single unicode character.
Fractional hours and minutes are not supported.
Reduced precision dates are not currently supported (YYYY-MM
, YYYY
).
Extended date representations are not currently supported (±YYYYYY-MM-DD
).
Ordinal dates are not currently supported (YYYY-OOO
).
Examples:
>>> from datetime import datetime >>> datetime.fromisoformat('2011-11-04') datetime.datetime(2011, 11, 4, 0, 0) >>> datetime.fromisoformat('20111104') datetime.datetime(2011, 11, 4, 0, 0) >>> datetime.fromisoformat('2011-11-04T00:05:23') datetime.datetime(2011, 11, 4, 0, 5, 23) >>> datetime.fromisoformat('2011-11-04T00:05:23Z') datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone.utc) >>> datetime.fromisoformat('20111104T000523') datetime.datetime(2011, 11, 4, 0, 5, 23) >>> datetime.fromisoformat('2011-W01-2T00:05:23.283') datetime.datetime(2011, 1, 4, 0, 5, 23, 283000) >>> datetime.fromisoformat('2011-11-04 00:05:23.283') datetime.datetime(2011, 11, 4, 0, 5, 23, 283000) >>> datetime.fromisoformat('2011-11-04 00:05:23.283+00:00') datetime.datetime(2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc) >>> datetime.fromisoformat('2011-11-04T00:05:23+04:00') datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))
Added in version 3.7.
Changed in version 3.11: Previously, this method only supported formats that could be emitted by date.isoformat()
or datetime.isoformat()
.
Return a datetime
corresponding to the ISO calendar date specified by year, week and day. The non-date components of the datetime are populated with their normal default values. This is the inverse of the function datetime.isocalendar()
.
Added in version 3.8.
Return a datetime
corresponding to date_string, parsed according to format.
If format does not contain microseconds or time zone information, this is equivalent to:
datetime(*(time.strptime(date_string, format)[0:6]))
ValueError
is raised if the date_string and format canât be parsed by time.strptime()
or if it returns a value which isnât a time tuple. See also strftime() and strptime() Behavior and datetime.fromisoformat()
.
Changed in version 3.13: If format specifies a day of month without a year a DeprecationWarning
is now emitted. This is to avoid a quadrennial leap year bug in code seeking to parse only a month and day as the default year used in absence of one in the format is not a leap year. Such format values may raise an error as of Python 3.15. The workaround is to always include a year in your format. If parsing date_string values that do not have a year, explicitly add a year that is a leap year before parsing:
>>> from datetime import datetime >>> date_string = "02/29" >>> when = datetime.strptime(f"{date_string};1984", "%m/%d;%Y") # Avoids leap year bug. >>> when.strftime("%B %d") 'February 29'
Class attributes:
The earliest representable datetime
, datetime(MINYEAR, 1, 1, tzinfo=None)
.
The latest representable datetime
, datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None)
.
The smallest possible difference between non-equal datetime
objects, timedelta(microseconds=1)
.
Instance attributes (read-only):
Between 1 and 12 inclusive.
Between 1 and the number of days in the given month of the given year.
In range(24)
.
In range(60)
.
In range(60)
.
In range(1000000)
.
The object passed as the tzinfo argument to the datetime
constructor, or None
if none was passed.
In [0, 1]
. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.
Added in version 3.6.
Supported operations:
Operation
Result
datetime2 = datetime1 + timedelta
(1)
datetime2 = datetime1 - timedelta
(2)
timedelta = datetime1 - datetime2
(3)
datetime1 == datetime2
datetime1 != datetime2
Equality comparison. (4)
datetime1 < datetime2
datetime1 > datetime2
datetime1 <= datetime2
datetime1 >= datetime2
Order comparison. (5)
datetime2
is a duration of timedelta
removed from datetime1
, moving forward in time if timedelta.days > 0
, or backward if timedelta.days < 0
. The result has the same tzinfo
attribute as the input datetime, and datetime2 - datetime1 == timedelta
after. OverflowError
is raised if datetime2.year
would be smaller than MINYEAR
or larger than MAXYEAR
. Note that no time zone adjustments are done even if the input is an aware object.
Computes the datetime2
such that datetime2 + timedelta == datetime1
. As for addition, the result has the same tzinfo
attribute as the input datetime, and no time zone adjustments are done even if the input is aware.
Subtraction of a datetime
from a datetime
is defined only if both operands are naive, or if both are aware. If one is aware and the other is naive, TypeError
is raised.
If both are naive, or both are aware and have the same tzinfo
attribute, the tzinfo
attributes are ignored, and the result is a timedelta
object t
such that datetime2 + t == datetime1
. No time zone adjustments are done in this case.
If both are aware and have different tzinfo
attributes, a-b
acts as if a
and b
were first converted to naive UTC datetimes. The result is (a.replace(tzinfo=None) - a.utcoffset()) - (b.replace(tzinfo=None) - b.utcoffset())
except that the implementation never overflows.
datetime
objects are equal if they represent the same date and time, taking into account the time zone.
Naive and aware datetime
objects are never equal.
If both comparands are aware, and have the same tzinfo
attribute, the tzinfo
and fold
attributes are ignored and the base datetimes are compared. If both comparands are aware and have different tzinfo
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows. datetime
instances in a repeated interval are never equal to datetime
instances in other time zone.
datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time, taking into account the time zone.
Order comparison between naive and aware datetime
objects raises TypeError
.
If both comparands are aware, and have the same tzinfo
attribute, the tzinfo
and fold
attributes are ignored and the base datetimes are compared. If both comparands are aware and have different tzinfo
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows.
Changed in version 3.3: Equality comparisons between aware and naive datetime
instances donât raise TypeError
.
Changed in version 3.13: Comparison between datetime
object and an instance of the date
subclass that is not a datetime
subclass no longer converts the latter to date
, ignoring the time part and the time zone. The default behavior can be changed by overriding the special comparison methods in subclasses.
Instance methods:
Return date
object with same year, month and day.
Return time
object with same hour, minute, second, microsecond and fold. tzinfo
is None
. See also method timetz()
.
Changed in version 3.6: The fold value is copied to the returned time
object.
Return time
object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also method time()
.
Changed in version 3.6: The fold value is copied to the returned time
object.
Return a new datetime
object with the same attributes, but with specified parameters updated. Note that tzinfo=None
can be specified to create a naive datetime from an aware datetime with no conversion of date and time data.
datetime
objects are also supported by generic function copy.replace()
.
Changed in version 3.6: Added the fold parameter.
Return a datetime
object with new tzinfo
attribute tz, adjusting the date and time data so the result is the same UTC time as self, but in tzâs local time.
If provided, tz must be an instance of a tzinfo
subclass, and its utcoffset()
and dst()
methods must not return None
. If self is naive, it is presumed to represent time in the system time zone.
If called without arguments (or with tz=None
) the system local time zone is assumed for the target time zone. The .tzinfo
attribute of the converted datetime instance will be set to an instance of timezone
with the zone name and offset obtained from the OS.
If self.tzinfo
is tz, self.astimezone(tz)
is equal to self: no adjustment of date or time data is performed. Else the result is local time in the time zone tz, representing the same UTC time as self: after astz = dt.astimezone(tz)
, astz - astz.utcoffset()
will have the same date and time data as dt - dt.utcoffset()
.
If you merely want to attach a timezone
object tz to a datetime dt without adjustment of date and time data, use dt.replace(tzinfo=tz)
. If you merely want to remove the timezone
object from an aware datetime dt without conversion of date and time data, use dt.replace(tzinfo=None)
.
Note that the default tzinfo.fromutc()
method can be overridden in a tzinfo
subclass to affect the result returned by astimezone()
. Ignoring error cases, astimezone()
acts like:
def astimezone(self, tz): if self.tzinfo is tz: return self # Convert self to UTC, and attach the new timezone object. utc = (self - self.utcoffset()).replace(tzinfo=tz) # Convert from UTC to tz's local time. return tz.fromutc(utc)
Changed in version 3.3: tz now can be omitted.
Changed in version 3.6: The astimezone()
method can now be called on naive instances that are presumed to represent system local time.
If tzinfo
is None
, returns None
, else returns self.tzinfo.utcoffset(self)
, and raises an exception if the latter doesnât return None
or a timedelta
object with magnitude less than one day.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
If tzinfo
is None
, returns None
, else returns self.tzinfo.dst(self)
, and raises an exception if the latter doesnât return None
or a timedelta
object with magnitude less than one day.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
If tzinfo
is None
, returns None
, else returns self.tzinfo.tzname(self)
, raises an exception if the latter doesnât return None
or a string object,
Return a time.struct_time
such as returned by time.localtime()
.
d.timetuple()
is equivalent to:
time.struct_time((d.year, d.month, d.day, d.hour, d.minute, d.second, d.weekday(), yday, dst))
where yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1
is the day number within the current year starting with 1 for January 1st. The tm_isdst
flag of the result is set according to the dst()
method: tzinfo
is None
or dst()
returns None
, tm_isdst
is set to -1
; else if dst()
returns a non-zero value, tm_isdst
is set to 1; else tm_isdst
is set to 0.
If datetime
instance d
is naive, this is the same as d.timetuple()
except that tm_isdst
is forced to 0 regardless of what d.dst()
returns. DST is never in effect for a UTC time.
If d
is aware, d
is normalized to UTC time, by subtracting d.utcoffset()
, and a time.struct_time
for the normalized time is returned. tm_isdst
is forced to 0. Note that an OverflowError
may be raised if d.year
was MINYEAR
or MAXYEAR
and UTC adjustment spills over a year boundary.
Warning
Because naive datetime
objects are treated by many datetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC; as a result, using datetime.utctimetuple()
may give misleading results. If you have a naive datetime
representing UTC, use datetime.replace(tzinfo=timezone.utc)
to make it aware, at which point you can use datetime.timetuple()
.
Return the proleptic Gregorian ordinal of the date. The same as self.date().toordinal()
.
Return POSIX timestamp corresponding to the datetime
instance. The return value is a float
similar to that returned by time.time()
.
Naive datetime
instances are assumed to represent local time and this method relies on the platform C mktime()
function to perform the conversion. Since datetime
supports wider range of values than mktime()
on many platforms, this method may raise OverflowError
or OSError
for times far in the past or far in the future.
For aware datetime
instances, the return value is computed as:
(dt - datetime(1970, 1, 1, tzinfo=timezone.utc)).total_seconds()
Added in version 3.3.
Changed in version 3.6: The timestamp()
method uses the fold
attribute to disambiguate the times during a repeated interval.
Note
There is no method to obtain the POSIX timestamp directly from a naive datetime
instance representing UTC time. If your application uses this convention and your system time zone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc
:
timestamp = dt.replace(tzinfo=timezone.utc).timestamp()
or by calculating the timestamp directly:
timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. The same as self.date().weekday()
. See also isoweekday()
.
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. The same as self.date().isoweekday()
. See also weekday()
, isocalendar()
.
Return a named tuple with three components: year
, week
and weekday
. The same as self.date().isocalendar()
.
Return a string representing the date and time in ISO 8601 format:
YYYY-MM-DDTHH:MM:SS.ffffff
, if microsecond
is not 0
YYYY-MM-DDTHH:MM:SS
, if microsecond
is 0
If utcoffset()
does not return None
, a string is appended, giving the UTC offset:
YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]
, if microsecond
is not 0
YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]]
, if microsecond
is 0
Examples:
>>> from datetime import datetime, timezone >>> datetime(2019, 5, 18, 15, 17, 8, 132263).isoformat() '2019-05-18T15:17:08.132263' >>> datetime(2019, 5, 18, 15, 17, tzinfo=timezone.utc).isoformat() '2019-05-18T15:17:00+00:00'
The optional argument sep (default 'T'
) is a one-character separator, placed between the date and time portions of the result. For example:
>>> from datetime import tzinfo, timedelta, datetime >>> class TZ(tzinfo): ... """A time zone with an arbitrary, constant -06:39 offset.""" ... def utcoffset(self, dt): ... return timedelta(hours=-6, minutes=-39) ... >>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ') '2002-12-25 00:00:00-06:39' >>> datetime(2009, 11, 27, microsecond=100, tzinfo=TZ()).isoformat() '2009-11-27T00:00:00.000100-06:39'
The optional argument timespec specifies the number of additional components of the time to include (the default is 'auto'
). It can be one of the following:
'auto'
: Same as 'seconds'
if microsecond
is 0, same as 'microseconds'
otherwise.
'hours'
: Include the hour
in the two-digit HH
format.
'seconds'
: Include hour
, minute
, and second
in HH:MM:SS
format.
'milliseconds'
: Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss
format.
'microseconds'
: Include full time in HH:MM:SS.ffffff
format.
Note
Excluded time components are truncated, not rounded.
ValueError
will be raised on an invalid timespec argument:
>>> from datetime import datetime >>> datetime.now().isoformat(timespec='minutes') '2002-12-25T00:00' >>> dt = datetime(2015, 1, 1, 12, 30, 59, 0) >>> dt.isoformat(timespec='microseconds') '2015-01-01T12:30:59.000000'
Changed in version 3.6: Added the timespec parameter.
For a datetime
instance d
, str(d)
is equivalent to d.isoformat(' ')
.
Return a string representing the date and time:
>>> from datetime import datetime >>> datetime(2002, 12, 4, 20, 30, 40).ctime() 'Wed Dec 4 20:30:40 2002'
The output string will not include time zone information, regardless of whether the input is aware or naive.
d.ctime()
is equivalent to:
time.ctime(time.mktime(d.timetuple()))
on platforms where the native C ctime()
function (which time.ctime()
invokes, but which datetime.ctime()
does not invoke) conforms to the C standard.
Return a string representing the date and time, controlled by an explicit format string. See also strftime() and strptime() Behavior and datetime.isoformat()
.
Same as datetime.strftime()
. This makes it possible to specify a format string for a datetime
object in formatted string literals and when using str.format()
. See also strftime() and strptime() Behavior and datetime.isoformat()
.
datetime
¶
Examples of working with datetime
objects:
>>> from datetime import datetime, date, time, timezone >>> # Using datetime.combine() >>> d = date(2005, 7, 14) >>> t = time(12, 30) >>> datetime.combine(d, t) datetime.datetime(2005, 7, 14, 12, 30) >>> # Using datetime.now() >>> datetime.now() datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1 >>> datetime.now(timezone.utc) datetime.datetime(2007, 12, 6, 15, 29, 43, 79060, tzinfo=datetime.timezone.utc) >>> # Using datetime.strptime() >>> dt = datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M") >>> dt datetime.datetime(2006, 11, 21, 16, 30) >>> # Using datetime.timetuple() to get tuple of all attributes >>> tt = dt.timetuple() >>> for it in tt: ... print(it) ... 2006 # year 11 # month 21 # day 16 # hour 30 # minute 0 # second 1 # weekday (0 = Monday) 325 # number of days since 1st January -1 # dst - method tzinfo.dst() returned None >>> # Date in ISO format >>> ic = dt.isocalendar() >>> for it in ic: ... print(it) ... 2006 # ISO year 47 # ISO week 2 # ISO weekday >>> # Formatting a datetime >>> dt.strftime("%A, %d. %B %Y %I:%M%p") 'Tuesday, 21. November 2006 04:30PM' >>> 'The {1} is {0:%d}, the {2} is {0:%B}, the {3} is {0:%I:%M%p}.'.format(dt, "day", "month", "time") 'The day is 21, the month is November, the time is 04:30PM.'
The example below defines a tzinfo
subclass capturing time zone information for Kabul, Afghanistan, which used +4 UTC until 1945 and then +4:30 UTC thereafter:
from datetime import timedelta, datetime, tzinfo, timezone class KabulTz(tzinfo): # Kabul used +4 until 1945, when they moved to +4:30 UTC_MOVE_DATE = datetime(1944, 12, 31, 20, tzinfo=timezone.utc) def utcoffset(self, dt): if dt.year < 1945: return timedelta(hours=4) elif (1945, 1, 1, 0, 0) <= dt.timetuple()[:5] < (1945, 1, 1, 0, 30): # An ambiguous ("imaginary") half-hour range representing # a 'fold' in time due to the shift from +4 to +4:30. # If dt falls in the imaginary range, use fold to decide how # to resolve. See PEP495. return timedelta(hours=4, minutes=(30 if dt.fold else 0)) else: return timedelta(hours=4, minutes=30) def fromutc(self, dt): # Follow same validations as in datetime.tzinfo if not isinstance(dt, datetime): raise TypeError("fromutc() requires a datetime argument") if dt.tzinfo is not self: raise ValueError("dt.tzinfo is not self") # A custom implementation is required for fromutc as # the input to this function is a datetime with utc values # but with a tzinfo set to self. # See datetime.astimezone or fromtimestamp. if dt.replace(tzinfo=timezone.utc) >= self.UTC_MOVE_DATE: return dt + timedelta(hours=4, minutes=30) else: return dt + timedelta(hours=4) def dst(self, dt): # Kabul does not observe daylight saving time. return timedelta(0) def tzname(self, dt): if dt >= self.UTC_MOVE_DATE: return "+04:30" return "+04"
Usage of KabulTz
from above:
>>> tz1 = KabulTz() >>> # Datetime before the change >>> dt1 = datetime(1900, 11, 21, 16, 30, tzinfo=tz1) >>> print(dt1.utcoffset()) 4:00:00 >>> # Datetime after the change >>> dt2 = datetime(2006, 6, 14, 13, 0, tzinfo=tz1) >>> print(dt2.utcoffset()) 4:30:00 >>> # Convert datetime to another time zone >>> dt3 = dt2.astimezone(timezone.utc) >>> dt3 datetime.datetime(2006, 6, 14, 8, 30, tzinfo=datetime.timezone.utc) >>> dt2 datetime.datetime(2006, 6, 14, 13, 0, tzinfo=KabulTz()) >>> dt2 == dt3 True
time
Objects¶
A time
object represents a (local) time of day, independent of any particular day, and subject to adjustment via a tzinfo
object.
All arguments are optional. tzinfo may be None
, or an instance of a tzinfo
subclass. The remaining arguments must be integers in the following ranges:
0 <= hour < 24
,
0 <= minute < 60
,
0 <= second < 60
,
0 <= microsecond < 1000000
,
fold in [0, 1]
.
If an argument outside those ranges is given, ValueError
is raised. All default to 0 except tzinfo, which defaults to None
.
Class attributes:
The earliest representable time
, time(0, 0, 0, 0)
.
The latest representable time
, time(23, 59, 59, 999999)
.
The smallest possible difference between non-equal time
objects, timedelta(microseconds=1)
, although note that arithmetic on time
objects is not supported.
Instance attributes (read-only):
In range(24)
.
In range(60)
.
In range(60)
.
In range(1000000)
.
The object passed as the tzinfo argument to the time
constructor, or None
if none was passed.
In [0, 1]
. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.
Added in version 3.6.
time
objects support equality and order comparisons, where a
is considered less than b
when a
precedes b
in time.
Naive and aware time
objects are never equal. Order comparison between naive and aware time
objects raises TypeError
.
If both comparands are aware, and have the same tzinfo
attribute, the tzinfo
and fold
attributes are ignored and the base times are compared. If both comparands are aware and have different tzinfo
attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset()
).
Changed in version 3.3: Equality comparisons between aware and naive time
instances donât raise TypeError
.
In Boolean contexts, a time
object is always considered to be true.
Changed in version 3.5: Before Python 3.5, a time
object was considered to be false if it represented midnight in UTC. This behavior was considered obscure and error-prone and has been removed in Python 3.5. See bpo-13936 for full details.
Other constructor:
Return a time
corresponding to a time_string in any valid ISO 8601 format, with the following exceptions:
Time zone offsets may have fractional seconds.
The leading T
, normally required in cases where there may be ambiguity between a date and a time, is not required.
Fractional seconds may have any number of digits (anything beyond 6 will be truncated).
Fractional hours and minutes are not supported.
Examples:
>>> from datetime import time >>> time.fromisoformat('04:23:01') datetime.time(4, 23, 1) >>> time.fromisoformat('T04:23:01') datetime.time(4, 23, 1) >>> time.fromisoformat('T042301') datetime.time(4, 23, 1) >>> time.fromisoformat('04:23:01.000384') datetime.time(4, 23, 1, 384) >>> time.fromisoformat('04:23:01,000384') datetime.time(4, 23, 1, 384) >>> time.fromisoformat('04:23:01+04:00') datetime.time(4, 23, 1, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400))) >>> time.fromisoformat('04:23:01Z') datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc) >>> time.fromisoformat('04:23:01+00:00') datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)
Added in version 3.7.
Changed in version 3.11: Previously, this method only supported formats that could be emitted by time.isoformat()
.
Instance methods:
Return a new time
with the same values, but with specified parameters updated. Note that tzinfo=None
can be specified to create a naive time
from an aware time
, without conversion of the time data.
time
objects are also supported by generic function copy.replace()
.
Changed in version 3.6: Added the fold parameter.
Return a string representing the time in ISO 8601 format, one of:
HH:MM:SS.ffffff
, if microsecond
is not 0
HH:MM:SS
, if microsecond
is 0
HH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]
, if utcoffset()
does not return None
HH:MM:SS+HH:MM[:SS[.ffffff]]
, if microsecond
is 0 and utcoffset()
does not return None
The optional argument timespec specifies the number of additional components of the time to include (the default is 'auto'
). It can be one of the following:
'auto'
: Same as 'seconds'
if microsecond
is 0, same as 'microseconds'
otherwise.
'hours'
: Include the hour
in the two-digit HH
format.
'seconds'
: Include hour
, minute
, and second
in HH:MM:SS
format.
'milliseconds'
: Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss
format.
'microseconds'
: Include full time in HH:MM:SS.ffffff
format.
Note
Excluded time components are truncated, not rounded.
ValueError
will be raised on an invalid timespec argument.
Example:
>>> from datetime import time >>> time(hour=12, minute=34, second=56, microsecond=123456).isoformat(timespec='minutes') '12:34' >>> dt = time(hour=12, minute=34, second=56, microsecond=0) >>> dt.isoformat(timespec='microseconds') '12:34:56.000000' >>> dt.isoformat(timespec='auto') '12:34:56'
Changed in version 3.6: Added the timespec parameter.
For a time t
, str(t)
is equivalent to t.isoformat()
.
Return a string representing the time, controlled by an explicit format string. See also strftime() and strptime() Behavior and time.isoformat()
.
Same as time.strftime()
. This makes it possible to specify a format string for a time
object in formatted string literals and when using str.format()
. See also strftime() and strptime() Behavior and time.isoformat()
.
If tzinfo
is None
, returns None
, else returns self.tzinfo.utcoffset(None)
, and raises an exception if the latter doesnât return None
or a timedelta
object with magnitude less than one day.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
If tzinfo
is None
, returns None
, else returns self.tzinfo.dst(None)
, and raises an exception if the latter doesnât return None
, or a timedelta
object with magnitude less than one day.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
If tzinfo
is None
, returns None
, else returns self.tzinfo.tzname(None)
, or raises an exception if the latter doesnât return None
or a string object.
time
¶
Examples of working with a time
object:
>>> from datetime import time, tzinfo, timedelta >>> class TZ1(tzinfo): ... def utcoffset(self, dt): ... return timedelta(hours=1) ... def dst(self, dt): ... return timedelta(0) ... def tzname(self,dt): ... return "+01:00" ... def __repr__(self): ... return f"{self.__class__.__name__}()" ... >>> t = time(12, 10, 30, tzinfo=TZ1()) >>> t datetime.time(12, 10, 30, tzinfo=TZ1()) >>> t.isoformat() '12:10:30+01:00' >>> t.dst() datetime.timedelta(0) >>> t.tzname() '+01:00' >>> t.strftime("%H:%M:%S %Z") '12:10:30 +01:00' >>> 'The {} is {:%H:%M}.'.format("time", t) 'The time is 12:10.'
tzinfo
Objects¶
This is an abstract base class, meaning that this class should not be instantiated directly. Define a subclass of tzinfo
to capture information about a particular time zone.
An instance of (a concrete subclass of) tzinfo
can be passed to the constructors for datetime
and time
objects. The latter objects view their attributes as being in local time, and the tzinfo
object supports methods revealing offset of local time from UTC, the name of the time zone, and DST offset, all relative to a date or time object passed to them.
You need to derive a concrete subclass, and (at least) supply implementations of the standard tzinfo
methods needed by the datetime
methods you use. The datetime
module provides timezone
, a simple concrete subclass of tzinfo
which can represent time zones with fixed offset from UTC such as UTC itself or North American EST and EDT.
Special requirement for pickling: A tzinfo
subclass must have an __init__()
method that can be called with no arguments, otherwise it can be pickled but possibly not unpickled again. This is a technical requirement that may be relaxed in the future.
A concrete subclass of tzinfo
may need to implement the following methods. Exactly which methods are needed depends on the uses made of aware datetime
objects. If in doubt, simply implement all of them.
Return offset of local time from UTC, as a timedelta
object that is positive east of UTC. If local time is west of UTC, this should be negative.
This represents the total offset from UTC; for example, if a tzinfo
object represents both time zone and DST adjustments, utcoffset()
should return their sum. If the UTC offset isnât known, return None
. Else the value returned must be a timedelta
object strictly between -timedelta(hours=24)
and timedelta(hours=24)
(the magnitude of the offset must be less than one day). Most implementations of utcoffset()
will probably look like one of these two:
return CONSTANT # fixed-offset class return CONSTANT + self.dst(dt) # daylight-aware class
If utcoffset()
does not return None
, dst()
should not return None
either.
The default implementation of utcoffset()
raises NotImplementedError
.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
Return the daylight saving time (DST) adjustment, as a timedelta
object or None
if DST information isnât known.
Return timedelta(0)
if DST is not in effect. If DST is in effect, return the offset as a timedelta
object (see utcoffset()
for details). Note that DST offset, if applicable, has already been added to the UTC offset returned by utcoffset()
, so thereâs no need to consult dst()
unless youâre interested in obtaining DST info separately. For example, datetime.timetuple()
calls its tzinfo
attributeâs dst()
method to determine how the tm_isdst
flag should be set, and tzinfo.fromutc()
calls dst()
to account for DST changes when crossing time zones.
An instance tz of a tzinfo
subclass that models both standard and daylight times must be consistent in this sense:
tz.utcoffset(dt) - tz.dst(dt)
must return the same result for every datetime
dt with dt.tzinfo == tz
. For sane tzinfo
subclasses, this expression yields the time zoneâs âstandard offsetâ, which should not depend on the date or the time, but only on geographic location. The implementation of datetime.astimezone()
relies on this, but cannot detect violations; itâs the programmerâs responsibility to ensure it. If a tzinfo
subclass cannot guarantee this, it may be able to override the default implementation of tzinfo.fromutc()
to work correctly with astimezone()
regardless.
Most implementations of dst()
will probably look like one of these two:
def dst(self, dt): # a fixed-offset class: doesn't account for DST return timedelta(0)
or:
def dst(self, dt): # Code to set dston and dstoff to the time zone's DST # transition times based on the input dt.year, and expressed # in standard local time. if dston <= dt.replace(tzinfo=None) < dstoff: return timedelta(hours=1) else: return timedelta(0)
The default implementation of dst()
raises NotImplementedError
.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
Return the time zone name corresponding to the datetime
object dt, as a string. Nothing about string names is defined by the datetime
module, and thereâs no requirement that it mean anything in particular. For example, "GMT"
, "UTC"
, "-500"
, "-5:00"
, "EDT"
, "US/Eastern"
, "America/New York"
are all valid replies. Return None
if a string name isnât known. Note that this is a method rather than a fixed string primarily because some tzinfo
subclasses will wish to return different names depending on the specific value of dt passed, especially if the tzinfo
class is accounting for daylight time.
The default implementation of tzname()
raises NotImplementedError
.
These methods are called by a datetime
or time
object, in response to their methods of the same names. A datetime
object passes itself as the argument, and a time
object passes None
as the argument. A tzinfo
subclassâs methods should therefore be prepared to accept a dt argument of None
, or of class datetime
.
When None
is passed, itâs up to the class designer to decide the best response. For example, returning None
is appropriate if the class wishes to say that time objects donât participate in the tzinfo
protocols. It may be more useful for utcoffset(None)
to return the standard UTC offset, as there is no other convention for discovering the standard offset.
When a datetime
object is passed in response to a datetime
method, dt.tzinfo
is the same object as self. tzinfo
methods can rely on this, unless user code calls tzinfo
methods directly. The intent is that the tzinfo
methods interpret dt as being in local time, and not need worry about objects in other time zones.
There is one more tzinfo
method that a subclass may wish to override:
This is called from the default datetime.astimezone()
implementation. When called from that, dt.tzinfo
is self, and dtâs date and time data are to be viewed as expressing a UTC time. The purpose of fromutc()
is to adjust the date and time data, returning an equivalent datetime in selfâs local time.
Most tzinfo
subclasses should be able to inherit the default fromutc()
implementation without problems. Itâs strong enough to handle fixed-offset time zones, and time zones accounting for both standard and daylight time, and the latter even if the DST transition times differ in different years. An example of a time zone the default fromutc()
implementation may not handle correctly in all cases is one where the standard offset (from UTC) depends on the specific date and time passed, which can happen for political reasons. The default implementations of astimezone()
and fromutc()
may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.
Skipping code for error cases, the default fromutc()
implementation acts like:
def fromutc(self, dt): # raise ValueError error if dt.tzinfo is not self dtoff = dt.utcoffset() dtdst = dt.dst() # raise ValueError if dtoff is None or dtdst is None delta = dtoff - dtdst # this is self's standard offset if delta: dt += delta # convert to standard local time dtdst = dt.dst() # raise ValueError if dtdst is None if dtdst: return dt + dtdst else: return dt
In the following tzinfo_examples.py
file there are some examples of tzinfo
classes:
from datetime import tzinfo, timedelta, datetime ZERO = timedelta(0) HOUR = timedelta(hours=1) SECOND = timedelta(seconds=1) # A class capturing the platform's idea of local time. # (May result in wrong values on historical times in # timezones where UTC offset and/or the DST rules had # changed in the past.) import time as _time STDOFFSET = timedelta(seconds = -_time.timezone) if _time.daylight: DSTOFFSET = timedelta(seconds = -_time.altzone) else: DSTOFFSET = STDOFFSET DSTDIFF = DSTOFFSET - STDOFFSET class LocalTimezone(tzinfo): def fromutc(self, dt): assert dt.tzinfo is self stamp = (dt - datetime(1970, 1, 1, tzinfo=self)) // SECOND args = _time.localtime(stamp)[:6] dst_diff = DSTDIFF // SECOND # Detect fold fold = (args == _time.localtime(stamp - dst_diff)) return datetime(*args, microsecond=dt.microsecond, tzinfo=self, fold=fold) def utcoffset(self, dt): if self._isdst(dt): return DSTOFFSET else: return STDOFFSET def dst(self, dt): if self._isdst(dt): return DSTDIFF else: return ZERO def tzname(self, dt): return _time.tzname[self._isdst(dt)] def _isdst(self, dt): tt = (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.weekday(), 0, 0) stamp = _time.mktime(tt) tt = _time.localtime(stamp) return tt.tm_isdst > 0 Local = LocalTimezone() # A complete implementation of current DST rules for major US time zones. def first_sunday_on_or_after(dt): days_to_go = 6 - dt.weekday() if days_to_go: dt += timedelta(days_to_go) return dt # US DST Rules # # This is a simplified (i.e., wrong for a few cases) set of rules for US # DST start and end times. For a complete and up-to-date set of DST rules # and timezone definitions, visit the Olson Database (or try pytz): # http://www.twinsun.com/tz/tz-link.htm # https://sourceforge.net/projects/pytz/ (might not be up-to-date) # # In the US, since 2007, DST starts at 2am (standard time) on the second # Sunday in March, which is the first Sunday on or after Mar 8. DSTSTART_2007 = datetime(1, 3, 8, 2) # and ends at 2am (DST time) on the first Sunday of Nov. DSTEND_2007 = datetime(1, 11, 1, 2) # From 1987 to 2006, DST used to start at 2am (standard time) on the first # Sunday in April and to end at 2am (DST time) on the last # Sunday of October, which is the first Sunday on or after Oct 25. DSTSTART_1987_2006 = datetime(1, 4, 1, 2) DSTEND_1987_2006 = datetime(1, 10, 25, 2) # From 1967 to 1986, DST used to start at 2am (standard time) on the last # Sunday in April (the one on or after April 24) and to end at 2am (DST time) # on the last Sunday of October, which is the first Sunday # on or after Oct 25. DSTSTART_1967_1986 = datetime(1, 4, 24, 2) DSTEND_1967_1986 = DSTEND_1987_2006 def us_dst_range(year): # Find start and end times for US DST. For years before 1967, return # start = end for no DST. if 2006 < year: dststart, dstend = DSTSTART_2007, DSTEND_2007 elif 1986 < year < 2007: dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006 elif 1966 < year < 1987: dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986 else: return (datetime(year, 1, 1), ) * 2 start = first_sunday_on_or_after(dststart.replace(year=year)) end = first_sunday_on_or_after(dstend.replace(year=year)) return start, end class USTimeZone(tzinfo): def __init__(self, hours, reprname, stdname, dstname): self.stdoffset = timedelta(hours=hours) self.reprname = reprname self.stdname = stdname self.dstname = dstname def __repr__(self): return self.reprname def tzname(self, dt): if self.dst(dt): return self.dstname else: return self.stdname def utcoffset(self, dt): return self.stdoffset + self.dst(dt) def dst(self, dt): if dt is None or dt.tzinfo is None: # An exception may be sensible here, in one or both cases. # It depends on how you want to treat them. The default # fromutc() implementation (called by the default astimezone() # implementation) passes a datetime with dt.tzinfo is self. return ZERO assert dt.tzinfo is self start, end = us_dst_range(dt.year) # Can't compare naive to aware objects, so strip the timezone from # dt first. dt = dt.replace(tzinfo=None) if start + HOUR <= dt < end - HOUR: # DST is in effect. return HOUR if end - HOUR <= dt < end: # Fold (an ambiguous hour): use dt.fold to disambiguate. return ZERO if dt.fold else HOUR if start <= dt < start + HOUR: # Gap (a non-existent hour): reverse the fold rule. return HOUR if dt.fold else ZERO # DST is off. return ZERO def fromutc(self, dt): assert dt.tzinfo is self start, end = us_dst_range(dt.year) start = start.replace(tzinfo=self) end = end.replace(tzinfo=self) std_time = dt + self.stdoffset dst_time = std_time + HOUR if end <= dst_time < end + HOUR: # Repeated hour return std_time.replace(fold=1) if std_time < start or dst_time >= end: # Standard time return std_time if start <= std_time < end - HOUR: # Daylight saving time return dst_time Eastern = USTimeZone(-5, "Eastern", "EST", "EDT") Central = USTimeZone(-6, "Central", "CST", "CDT") Mountain = USTimeZone(-7, "Mountain", "MST", "MDT") Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")
Note that there are unavoidable subtleties twice per year in a tzinfo
subclass accounting for both standard and daylight time, at the DST transition points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the minute after 1:59 (EST) on the second Sunday in March, and ends the minute after 1:59 (EDT) on the first Sunday in November:
UTC 3:MM 4:MM 5:MM 6:MM 7:MM 8:MM EST 22:MM 23:MM 0:MM 1:MM 2:MM 3:MM EDT 23:MM 0:MM 1:MM 2:MM 3:MM 4:MM start 22:MM 23:MM 0:MM 1:MM 3:MM 4:MM end 23:MM 0:MM 1:MM 1:MM 2:MM 3:MM
When DST starts (the âstartâ line), the local wall clock leaps from 1:59 to 3:00. A wall time of the form 2:MM doesnât really make sense on that day, so astimezone(Eastern)
wonât deliver a result with hour == 2
on the day DST begins. For example, at the Spring forward transition of 2016, we get:
>>> from datetime import datetime, timezone >>> from tzinfo_examples import HOUR, Eastern >>> u0 = datetime(2016, 3, 13, 5, tzinfo=timezone.utc) >>> for i in range(4): ... u = u0 + i*HOUR ... t = u.astimezone(Eastern) ... print(u.time(), 'UTC =', t.time(), t.tzname()) ... 05:00:00 UTC = 00:00:00 EST 06:00:00 UTC = 01:00:00 EST 07:00:00 UTC = 03:00:00 EDT 08:00:00 UTC = 04:00:00 EDT
When DST ends (the âendâ line), thereâs a potentially worse problem: thereâs an hour that canât be spelled unambiguously in local wall time: the last hour of daylight time. In Eastern, thatâs times of the form 5:MM UTC on the day daylight time ends. The local wall clock leaps from 1:59 (daylight time) back to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous. astimezone()
mimics the local clockâs behavior by mapping two adjacent UTC hours into the same local hour then. In the Eastern example, UTC times of the form 5:MM and 6:MM both map to 1:MM when converted to Eastern, but earlier times have the fold
attribute set to 0 and the later times have it set to 1. For example, at the Fall back transition of 2016, we get:
>>> u0 = datetime(2016, 11, 6, 4, tzinfo=timezone.utc) >>> for i in range(4): ... u = u0 + i*HOUR ... t = u.astimezone(Eastern) ... print(u.time(), 'UTC =', t.time(), t.tzname(), t.fold) ... 04:00:00 UTC = 00:00:00 EDT 0 05:00:00 UTC = 01:00:00 EDT 0 06:00:00 UTC = 01:00:00 EST 1 07:00:00 UTC = 02:00:00 EST 0
Note that the datetime
instances that differ only by the value of the fold
attribute are considered equal in comparisons.
Applications that canât bear wall-time ambiguities should explicitly check the value of the fold
attribute or avoid using hybrid tzinfo
subclasses; there are no ambiguities when using timezone
, or any other fixed-offset tzinfo
subclass (such as a class representing only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).
See also
zoneinfo
The
datetime
module has a basictimezone
class (for handling arbitrary fixed offsets from UTC) and itstimezone.utc
attribute (a UTCtimezone
instance).
zoneinfo
brings the IANA time zone database (also known as the Olson database) to Python, and its usage is recommended.
The Time Zone Database (often called tz, tzdata or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.
timezone
Objects¶
The timezone
class is a subclass of tzinfo
, each instance of which represents a time zone defined by a fixed offset from UTC.
Objects of this class cannot be used to represent time zone information in the locations where different offsets are used in different days of the year or where historical changes have been made to civil time.
The offset argument must be specified as a timedelta
object representing the difference between the local time and UTC. It must be strictly between -timedelta(hours=24)
and timedelta(hours=24)
, otherwise ValueError
is raised.
The name argument is optional. If specified it must be a string that will be used as the value returned by the datetime.tzname()
method.
Added in version 3.2.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
Return the fixed value specified when the timezone
instance is constructed.
The dt argument is ignored. The return value is a timedelta
instance equal to the difference between the local time and UTC.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
Return the fixed value specified when the timezone
instance is constructed.
If name is not provided in the constructor, the name returned by tzname(dt)
is generated from the value of the offset
as follows. If offset is timedelta(0)
, the name is âUTCâ, otherwise it is a string in the format UTC±HH:MM
, where ± is the sign of offset
, HH and MM are two digits of offset.hours
and offset.minutes
respectively.
Changed in version 3.6: Name generated from offset=timedelta(0)
is now plain 'UTC'
, not 'UTC+00:00'
.
Always returns None
.
Return dt + offset
. The dt argument must be an aware datetime
instance, with tzinfo
set to self
.
Class attributes:
The UTC time zone, timezone(timedelta(0))
.
strftime()
and strptime()
Behavior¶
date
, datetime
, and time
objects all support a strftime(format)
method, to create a string representing the time under the control of an explicit format string.
Conversely, the datetime.strptime()
class method creates a datetime
object from a string representing a date and time and a corresponding format string.
The table below provides a high-level comparison of strftime()
versus strptime()
:
strftime
strptime
Usage
Convert object to a string according to a given format
Parse a string into a datetime
object given a corresponding format
Type of method
Instance method
Class method
Method of
Signature
strftime(format)
strptime(date_string, format)
strftime()
and strptime()
Format Codes¶
These methods accept format codes that can be used to parse and format dates:
>>> datetime.strptime('31/01/22 23:59:59.999999', ... '%d/%m/%y %H:%M:%S.%f') datetime.datetime(2022, 1, 31, 23, 59, 59, 999999) >>> _.strftime('%a %d %b %Y, %I:%M%p') 'Mon 31 Jan 2022, 11:59PM'
The following is a list of all the format codes that the 1989 C standard requires, and these work on all platforms with a standard C implementation.
Directive
Meaning
Example
Notes
%a
Weekday as localeâs abbreviated name.
Sun, Mon, â¦, Sat (en_US);
So, Mo, â¦, Sa (de_DE)
(1)
%A
Weekday as localeâs full name.
Sunday, Monday, â¦, Saturday (en_US);
Sonntag, Montag, â¦, Samstag (de_DE)
(1)
%w
Weekday as a decimal number, where 0 is Sunday and 6 is Saturday.
0, 1, â¦, 6
%d
Day of the month as a zero-padded decimal number.
01, 02, â¦, 31
(9)
%b
Month as localeâs abbreviated name.
Jan, Feb, â¦, Dec (en_US);
Jan, Feb, â¦, Dez (de_DE)
(1)
%B
Month as localeâs full name.
January, February, â¦, December (en_US);
Januar, Februar, â¦, Dezember (de_DE)
(1)
%m
Month as a zero-padded decimal number.
01, 02, â¦, 12
(9)
%y
Year without century as a zero-padded decimal number.
00, 01, â¦, 99
(9)
%Y
Year with century as a decimal number.
0001, 0002, â¦, 2013, 2014, â¦, 9998, 9999
(2)
%H
Hour (24-hour clock) as a zero-padded decimal number.
00, 01, â¦, 23
(9)
%I
Hour (12-hour clock) as a zero-padded decimal number.
01, 02, â¦, 12
(9)
%p
Localeâs equivalent of either AM or PM.
AM, PM (en_US);
am, pm (de_DE)
(1), (3)
%M
Minute as a zero-padded decimal number.
00, 01, â¦, 59
(9)
%S
Second as a zero-padded decimal number.
00, 01, â¦, 59
(4), (9)
%f
Microsecond as a decimal number, zero-padded to 6 digits.
000000, 000001, â¦, 999999
(5)
%z
UTC offset in the form ±HHMM[SS[.ffffff]]
(empty string if the object is naive).
(empty), +0000, -0400, +1030, +063415, -030712.345216
(6)
%Z
Time zone name (empty string if the object is naive).
(empty), UTC, GMT
(6)
%j
Day of the year as a zero-padded decimal number.
001, 002, â¦, 366
(9)
%U
Week number of the year (Sunday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.
00, 01, â¦, 53
(7), (9)
%W
Week number of the year (Monday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Monday are considered to be in week 0.
00, 01, â¦, 53
(7), (9)
%c
Localeâs appropriate date and time representation.
Tue Aug 16 21:30:00 1988 (en_US);
Di 16 Aug 21:30:00 1988 (de_DE)
(1)
%x
Localeâs appropriate date representation.
08/16/88 (None);
08/16/1988 (en_US);
16.08.1988 (de_DE)
(1)
%X
Localeâs appropriate time representation.
21:30:00 (en_US);
21:30:00 (de_DE)
(1)
%%
A literal '%'
character.
%
Several additional directives not required by the C89 standard are included for convenience. These parameters all correspond to ISO 8601 date values.
Directive
Meaning
Example
Notes
%G
ISO 8601 year with century representing the year that contains the greater part of the ISO week (%V
).
0001, 0002, â¦, 2013, 2014, â¦, 9998, 9999
(8)
%u
ISO 8601 weekday as a decimal number where 1 is Monday.
1, 2, â¦, 7
%V
ISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4.
01, 02, â¦, 53
(8), (9)
%:z
UTC offset in the form ±HH:MM[:SS[.ffffff]]
(empty string if the object is naive).
(empty), +00:00, -04:00, +10:30, +06:34:15, -03:07:12.345216
(6)
These may not be available on all platforms when used with the strftime()
method. The ISO 8601 year and ISO 8601 week directives are not interchangeable with the year and week number directives above. Calling strptime()
with incomplete or ambiguous ISO 8601 directives will raise a ValueError
.
The full set of format codes supported varies across platforms, because Python calls the platform C libraryâs strftime()
function, and platform variations are common. To see the full set of format codes supported on your platform, consult the strftime(3) documentation. There are also differences between platforms in handling of unsupported format specifiers.
Added in version 3.6: %G
, %u
and %V
were added.
Added in version 3.12: %:z
was added.
Broadly speaking, d.strftime(fmt)
acts like the time
moduleâs time.strftime(fmt, d.timetuple())
although not all objects support a timetuple()
method.
For the datetime.strptime()
class method, the default value is 1900-01-01T00:00:00.000
: any components not specified in the format string will be pulled from the default value. [4]
Using datetime.strptime(date_string, format)
is equivalent to:
datetime(*(time.strptime(date_string, format)[0:6]))
except when the format includes sub-second components or time zone offset information, which are supported in datetime.strptime
but are discarded by time.strptime
.
For time
objects, the format codes for year, month, and day should not be used, as time
objects have no such values. If theyâre used anyway, 1900 is substituted for the year, and 1 for the month and day.
For date
objects, the format codes for hours, minutes, seconds, and microseconds should not be used, as date
objects have no such values. If theyâre used anyway, 0 is substituted for them.
For the same reason, handling of format strings containing Unicode code points that canât be represented in the charset of the current locale is also platform-dependent. On some platforms such code points are preserved intact in the output, while on others strftime
may raise UnicodeError
or return an empty string instead.
Notes:
Because the format depends on the current locale, care should be taken when making assumptions about the output value. Field orderings will vary (for example, âmonth/day/yearâ versus âday/month/yearâ), and the output may contain non-ASCII characters.
The strptime()
method can parse years in the full [1, 9999] range, but years < 1000 must be zero-filled to 4-digit width.
Changed in version 3.2: In previous versions, strftime()
method was restricted to years >= 1900.
Changed in version 3.3: In version 3.2, strftime()
method was restricted to years >= 1000.
When used with the strptime()
method, the %p
directive only affects the output hour field if the %I
directive is used to parse the hour.
Unlike the time
module, the datetime
module does not support leap seconds.
When used with the strptime()
method, the %f
directive accepts from one to six digits and zero pads on the right. %f
is an extension to the set of format characters in the C standard (but implemented separately in datetime objects, and therefore always available).
For a naive object, the %z
, %:z
and %Z
format codes are replaced by empty strings.
For an aware object:
%z
utcoffset()
is transformed into a string of the form ±HHMM[SS[.ffffff]]
, where HH
is a 2-digit string giving the number of UTC offset hours, MM
is a 2-digit string giving the number of UTC offset minutes, SS
is a 2-digit string giving the number of UTC offset seconds and ffffff
is a 6-digit string giving the number of UTC offset microseconds. The ffffff
part is omitted when the offset is a whole number of seconds and both the ffffff
and the SS
part is omitted when the offset is a whole number of minutes. For example, if utcoffset()
returns timedelta(hours=-3, minutes=-30)
, %z
is replaced with the string '-0330'
.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
Changed in version 3.7: When the %z
directive is provided to the strptime()
method, the UTC offsets can have a colon as a separator between hours, minutes and seconds. For example, '+01:00:00'
will be parsed as an offset of one hour. In addition, providing 'Z'
is identical to '+00:00'
.
%:z
Behaves exactly as %z
, but has a colon separator added between hours, minutes and seconds.
%Z
In strftime()
, %Z
is replaced by an empty string if tzname()
returns None
; otherwise %Z
is replaced by the returned value, which must be a string.
strptime()
only accepts certain values for %Z
:
any value in time.tzname
for your machineâs locale
the hard-coded values UTC
and GMT
So someone living in Japan may have JST
, UTC
, and GMT
as valid values, but probably not EST
. It will raise ValueError
for invalid values.
Changed in version 3.2: When the %z
directive is provided to the strptime()
method, an aware datetime
object will be produced. The tzinfo
of the result will be set to a timezone
instance.
When used with the strptime()
method, %U
and %W
are only used in calculations when the day of the week and the calendar year (%Y
) are specified.
Similar to %U
and %W
, %V
is only used in calculations when the day of the week and the ISO year (%G
) are specified in a strptime()
format string. Also note that %G
and %Y
are not interchangeable.
When used with the strptime()
method, the leading zero is optional for formats %d
, %m
, %H
, %I
, %M
, %S
, %j
, %U
, %W
, and %V
. Format %y
does require a leading zero.
When parsing a month and day using strptime()
, always include a year in the format. If the value you need to parse lacks a year, append an explicit dummy leap year. Otherwise your code will raise an exception when it encounters leap day because the default year used by the parser is not a leap year. Users run into this bug every four yearsâ¦
>>> month_day = "02/29" >>> datetime.strptime(f"{month_day};1984", "%m/%d;%Y") # No leap year bug. datetime.datetime(1984, 2, 29, 0, 0)
Deprecated since version 3.13, will be removed in version 3.15: strptime()
calls using a format string containing a day of month without a year now emit a DeprecationWarning
. In 3.15 or later we may change this into an error or change the default year to a leap year. See gh-70647.
Footnotes
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