datetime — Basic date and time types¶

Aware and Naive Objects¶

Date and time objects may be categorized as “aware” or “naive” 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.

Constants¶

The datetime module exports the following constants:

datetime.MINYEAR¶

The smallest year number allowed in a date or datetime object. MINYEAR is 1.

datetime.MAXYEAR¶

The largest year number allowed in a date or datetime object. MAXYEAR is 9999.

datetime.UTC¶

Alias for the UTC time zone singleton datetime.timezone.utc.

Added in version 3.11.

Available Types¶

class datetime.date

An idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes: year, month, and day.

class datetime.time

An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. (There is no notion of “leap seconds” here.) Attributes: hour, minute, second, microsecond, and tzinfo.

class datetime.datetime

A combination of a date and a time. Attributes: year, month, day, hour, minute, second, microsecond, and tzinfo.

class datetime.timedelta

A duration expressing the difference between two datetime or date instances to microsecond resolution.

class datetime.tzinfo

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).

class datetime.timezone

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
        datetime

timedelta Objects¶

A timedelta object represents a duration, the difference between two datetime or date instances.

class datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)¶

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 “merged” 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:

timedelta.min¶

The most negative timedelta object, timedelta(-999999999).

timedelta.max¶

The most positive timedelta object, timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999).

timedelta.resolution¶

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):

timedelta.days¶

Between -999,999,999 and 999,999,999 inclusive.

timedelta.seconds¶

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

timedelta.microseconds¶

Between 0 and 999,999 inclusive.

Supported operations:

Notes:

1. This is exact but may overflow.

2. This is exact and cannot overflow.

3. Division by zero raises ZeroDivisionError.

4. -timedelta.max is not representable as a timedelta object.

5. 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
   

6. 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).

timedelta objects support equality and order comparisons.

In Boolean contexts, a timedelta object is considered to be true if and only if it isn’t equal to timedelta(0).

Instance methods:

timedelta.total_seconds()¶

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.

>>> # 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

>>> 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]

class datetime.date(year, month, day)¶

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:

classmethod date.today()¶

Return the current local date.

This is equivalent to date.fromtimestamp(time.time()).

classmethod date.fromtimestamp(timestamp)¶

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. It’s 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.

classmethod date.fromordinal(ordinal)¶

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.

classmethod date.fromisoformat(date_string)¶

Return a date corresponding to a date_string given in any valid ISO 8601 format, with the following exceptions:

1. Reduced precision dates are not currently supported (YYYY-MM, YYYY).

2. Extended date representations are not currently supported (±YYYYYY-MM-DD).

3. 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.

classmethod date.fromisocalendar(year, week, day)¶

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:

date.min¶

The earliest representable date, date(MINYEAR, 1, 1).

date.max¶

The latest representable date, date(MAXYEAR, 12, 31).

date.resolution¶

The smallest possible difference between non-equal date objects, timedelta(days=1).

Instance attributes (read-only):

date.year¶

Between MINYEAR and MAXYEAR inclusive.

date.month¶

Between 1 and 12 inclusive.

date.day¶

Between 1 and the number of days in the given month of the given year.

Supported operations:

Notes:

1. 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.

2. timedelta.seconds and timedelta.microseconds are ignored.

3. This is exact, and cannot overflow. timedelta.seconds and timedelta.microseconds are 0, and date2 + timedelta == date1 after.

4. 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.

5. 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.

In Boolean contexts, all date objects are considered to be true.

Instance methods:

date.replace(year=self.year, month=self.month, day=self.day)¶

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.

date.timetuple()¶

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.

date.toordinal()¶

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.

date.weekday()¶

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().

date.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().

date.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.

date.isoformat()¶

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'

date.__str__()¶

For a date d, str(d) is equivalent to d.isoformat().

date.ctime()¶

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.

date.strftime(format)¶

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().

date.__format__(format)¶

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().

>>> 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

>>> 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:

class datetime.datetime(year, month, day, hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0)¶

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:

classmethod datetime.today()¶

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.

classmethod datetime.now(tz=None)¶

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 tz’s 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.

classmethod datetime.utcnow()¶

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.

classmethod datetime.fromtimestamp(timestamp, tz=None)¶

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 platform’s 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 tz’s 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. It’s 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 it’s 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.

classmethod datetime.utcfromtimestamp(timestamp)¶

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. It’s 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.

classmethod datetime.fromordinal(ordinal)¶

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.

classmethod datetime.combine(date, time, tzinfo=time.tzinfo)¶

Return a new datetime object whose date components are equal to the given date object’s, and whose time components are equal to the given time object’s. 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.

classmethod datetime.fromisoformat(date_string)¶

Return a datetime corresponding to a date_string in any valid ISO 8601 format, with the following exceptions:

1. Time zone offsets may have fractional seconds.

2. The T separator may be replaced by any single unicode character.

3. Fractional hours and minutes are not supported.

4. Reduced precision dates are not currently supported (YYYY-MM, YYYY).

5. Extended date representations are not currently supported (±YYYYYY-MM-DD).

6. 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().

classmethod datetime.fromisocalendar(year, week, day)¶

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.

classmethod datetime.strptime(date_string, format)¶

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 can’t be parsed by time.strptime() or if it returns a value which isn’t 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:

datetime.min¶

The earliest representable datetime, datetime(MINYEAR, 1, 1, tzinfo=None).

datetime.max¶

The latest representable datetime, datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None).

datetime.resolution¶

The smallest possible difference between non-equal datetime objects, timedelta(microseconds=1).

Instance attributes (read-only):

datetime.year¶

Between MINYEAR and MAXYEAR inclusive.

datetime.month¶

Between 1 and 12 inclusive.

datetime.day¶

Between 1 and the number of days in the given month of the given year.

datetime.hour¶

In range(24).

datetime.minute¶

In range(60).

datetime.second¶

In range(60).

datetime.microsecond¶

In range(1000000).

datetime.tzinfo¶

The object passed as the tzinfo argument to the datetime constructor, or None if none was passed.

datetime.fold¶

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:

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

Instance methods:

datetime.date()¶

Return date object with same year, month and day.

datetime.time()¶

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.

datetime.timetz()