New in version 2.3.
The datetime
module supplies classes for manipulating dates and times in both simple and complex ways. While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation. For related functionality, see also the time
and calendar
modules.
There are two kinds of date and time objects: “naive” and “aware”.
An aware object has sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, to locate itself relative to other aware objects. An aware object is used to represent 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 timezone is purely up to the program, just like it’s 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. Note that no concrete tzinfo
classes are supplied by the datetime
module. Supporting timezones at whatever level of detail is required is up to the application. The rules for time adjustment across the world are more political than rational, and there is no standard suitable for every application.
The datetime
module exports the following constants:
See also
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 date
, time
, or datetime
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).
Objects of these types are immutable.
Objects of the date
type are always naive.
An object of type time
or datetime
may be naive or aware. A datetime
object d is aware if d.tzinfo
is not None
and d.tzinfo.utcoffset(d)
does not return None
. If d.tzinfo
is None
, or if d.tzinfo
is not None
but d.tzinfo.utcoffset(d)
returns None
, d is naive. A time
object t is aware if t.tzinfo
is not None
and t.tzinfo.utcoffset(None)
does not return None
. Otherwise, t is naive.
The distinction between naive and aware doesn’t apply to timedelta
objects.
Subclass relationships:
object timedelta tzinfo time date datetime
A timedelta
object represents a duration, the difference between two dates or times.
class datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])
All arguments are optional and default to 0
. Arguments may be ints, longs, or floats, and may be positive or negative.
Only days, seconds and microseconds are stored internally. Arguments are converted to those units:
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
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. 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)
Class attributes are:
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
> -timedelta.min
. -timedelta.max
is not representable as a timedelta
object.
Instance attributes (read-only):
Attribute | Value |
---|---|
| Between -999999999 and 999999999 inclusive |
| Between 0 and 86399 inclusive |
| Between 0 and 999999 inclusive |
Supported operations:
Operation | Result |
---|---|
| Sum of t2 and t3. Afterwards t1-t2 == t3 and t1-t3 == t2 are true. (1) |
| Difference of t2 and t3. Afterwards t1 == t2 - t3 and t2 == t1 + t3 are true. (1) |
| Delta multiplied by an integer or long. Afterwards t1 // i == t2 is true, provided |
In general, t1 * i == t1 * (i-1) + t1 is true. (1) | |
| The floor is computed and the remainder (if any) is thrown away. (3) |
| Returns a |
| equivalent to |
| equivalent to +t when |
| Returns a string in the form |
| Returns a string in the form |
Notes:
ZeroDivisionError
.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(-1, 68400) >>> print(_) -1 day, 19:00:00
In addition to the operations listed above timedelta
objects support certain additions and subtractions with date
and datetime
objects (see below).
Comparisons of timedelta
objects are supported with the timedelta
object representing the smaller duration considered to be the smaller timedelta. In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a timedelta
object is compared to an object of a different type, TypeError
is raised unless the comparison is ==
or !=
. The latter cases return False
or True
, respectively.
timedelta
objects are hashable (usable as dictionary keys), support efficient pickling, and 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.microseconds + (td.seconds + td.days * 24 *
3600) * 10**6) / 10**6
computed with true division enabled.
Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.
New in version 2.7.
Example usage:
>>> from datetime import timedelta >>> year = timedelta(days=365) >>> another_year = timedelta(weeks=40, days=84, hours=23, ... minutes=50, seconds=600) # adds up to 365 days >>> year.total_seconds() 31536000.0 >>> year == another_year True >>> ten_years = 10 * year >>> ten_years, ten_years.days // 365 (datetime.timedelta(3650), 10) >>> nine_years = ten_years - year >>> nine_years, nine_years.days // 365 (datetime.timedelta(3285), 9) >>> three_years = nine_years // 3; >>> three_years, three_years.days // 365 (datetime.timedelta(1095), 3) >>> abs(three_years - ten_years) == 2 * three_years + year True
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. This matches the definition of the “proleptic Gregorian” calendar in Dershowitz and Reingold’s book Calendrical Calculations, where it’s the base calendar for all computations. See the book for algorithms for converting between proleptic Gregorian ordinals and many other calendar systems.
class datetime.date(year, month, day)
All arguments are required. Arguments may be ints or longs, 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 ValueError
, if the timestamp is out of the range of values supported by the platform C localtime()
function. 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()
.
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
.
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.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:
Operation | Result |
---|---|
| date2 is |
| Computes date2 such that |
| (3) |
| date1 is considered less than date2 when date1 precedes date2 in time. (4) |
Notes:
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.date1 < date2
if and only if date1.toordinal() <
date2.toordinal()
. In order to stop comparison from falling back to the default scheme of comparing object addresses, date comparison normally raises TypeError
if the other comparand isn’t also a date
object. However, NotImplemented
is returned instead if the other comparand has a timetuple()
attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a date
object is compared to an object of a different type, TypeError
is raised unless the comparison is ==
or !=
. The latter cases return False
or True
, respectively.Dates can be used as dictionary keys. In Boolean contexts, all date
objects are considered to be true.
Instance methods:
date.replace(year, month, day)
Return a date with the same value, except for those parameters given new values by whichever keyword arguments are specified. For example, if d ==
date(2002, 12, 31)
, then d.replace(day=26) == date(2002, 12, 26)
.
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 3-tuple, (ISO year, ISO week number, ISO weekday).
The ISO calendar is a widely used variant of the Gregorian calendar. See https://www.staff.science.uu.nl/~gent0113/calendar/isocalendar.htm for a good explanation.
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, so that date(2003, 12, 29).isocalendar() == (2004, 1, 1)
and date(2004, 1,
4).isocalendar() == (2004, 1, 7)
.
date.isoformat()
Return a string representing the date in ISO 8601 format, ‘YYYY-MM-DD’. For example, 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, for example 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. For a complete list of formatting directives, see section strftime() and strptime() Behavior.
date.__format__(format)
Same as date.strftime()
. This makes it possible to specify a format string for a date
object when using str.format()
. See section strftime() and strptime() Behavior.
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
Example of working with date
:
>>> from datetime import date >>> d = date.fromordinal(730920) # 730920th day after 1. 1. 0001 >>> d datetime.date(2002, 3, 11) >>> 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 ) >>> d.isoformat() '2002-03-11' >>> d.strftime("%d/%m/%y") '11/03/02' >>> d.strftime("%A %d. %B %Y") 'Monday 11. March 2002' >>> 'The {1} is {0:%d}, the {2} is {0:%B}.'.format(d, "day", "month") 'The day is 11, the month is March.'
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[, minute[, second[, microsecond[, tzinfo]]]]])
The year, month and day arguments are required. tzinfo may be None
, or an instance of a tzinfo
subclass. The remaining arguments may be ints or longs, 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
If an argument outside those ranges is given, ValueError
is raised.
Other constructors, all class methods:
classmethod datetime.today()
Return the current local datetime, with tzinfo
None
. This is equivalent to datetime.fromtimestamp(time.time())
. See also now()
, fromtimestamp()
.
classmethod datetime.now([tz])
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. In this case the result is equivalent to tz.fromutc(datetime.utcnow().replace(tzinfo=tz))
. See also today()
, utcnow()
.
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. See also now()
.
classmethod datetime.fromtimestamp(timestamp[, tz])
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. In this case the result is equivalent to tz.fromutc(datetime.utcfromtimestamp(timestamp).replace(tzinfo=tz))
.
fromtimestamp()
may raise ValueError
, if the timestamp is out of the range of values supported by the platform C localtime()
or gmtime()
functions. 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. See also utcfromtimestamp()
.
classmethod datetime.utcfromtimestamp(timestamp)
Return the UTC datetime
corresponding to the POSIX timestamp, with tzinfo
None
. This may raise ValueError
, if the timestamp is out of the range of values supported by the platform C gmtime()
function. It’s common for this to be restricted to years in 1970 through 2038. See also fromtimestamp()
.
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)
Return a new datetime
object whose date components are equal to the given date
object’s, and whose time components and tzinfo
attributes are equal to the given time
object’s. For any datetime
object d, d == datetime.combine(d.date(), d.timetz())
. If date is a datetime
object, its time components and tzinfo
attributes are ignored.
classmethod datetime.strptime(date_string, format)
Return a datetime
corresponding to date_string, parsed according to format. 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. For a complete list of formatting directives, see section strftime() and strptime() Behavior.
New in version 2.5.
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.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.
Supported operations:
Operation | Result |
---|---|
| (1) |
| (2) |
| (3) |
|
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.tzinfo
attribute as the input datetime, and no time zone adjustments are done even if the input is aware. This isn’t quite equivalent to datetime1 + (-timedelta), because -timedelta in isolation can overflow in cases where datetime1 - timedelta does not.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 first. The result is (a.replace(tzinfo=None) - a.utcoffset()) - (b.replace(tzinfo=None)
- b.utcoffset())
except that the implementation never overflows.
datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time.
If one comparand is naive and the other is aware, TypeError
is raised. If both comparands are aware, and have the same tzinfo
attribute, the common tzinfo
attribute is ignored and the base datetimes 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()
).
Note
In order to stop comparison from falling back to the default scheme of comparing object addresses, datetime comparison normally raises TypeError
if the other comparand isn’t also a datetime
object. However, NotImplemented
is returned instead if the other comparand has a timetuple()
attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a datetime
object is compared to an object of a different type, TypeError
is raised unless the comparison is ==
or !=
. The latter cases return False
or True
, respectively.
datetime
objects can be used as dictionary keys. In Boolean contexts, all datetime
objects are considered to be true.
Instance methods:
datetime.date()
Return date
object with same year, month and day.
datetime.time()
Return time
object with same hour, minute, second and microsecond. tzinfo
is None
. See also method timetz()
.
datetime.timetz()
Return time
object with same hour, minute, second, microsecond, and tzinfo attributes. See also method time()
.
datetime.replace([year[, month[, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]]]]])
Return a datetime with the same attributes, except for those attributes given new values by whichever keyword arguments are specified. 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.astimezone(tz)
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 tz’s local time.
tz must be an instance of a tzinfo
subclass, and its utcoffset()
and dst()
methods must not return None
. self must be aware (self.tzinfo
must not be None
, and self.utcoffset()
must not return None
).
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 time zone tz, representing the same UTC time as self: after astz = dt.astimezone(tz)
, astz - astz.utcoffset()
will usually have the same date and time data as dt - dt.utcoffset()
. The discussion of class tzinfo
explains the cases at Daylight Saving Time transition boundaries where this cannot be achieved (an issue only if tz models both standard and daylight time).
If you merely want to attach a time zone 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 time zone 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 time zone object. utc = (self - self.utcoffset()).replace(tzinfo=tz) # Convert from UTC to tz's local time. return tz.fromutc(utc)
datetime.utcoffset()
If tzinfo
is None
, returns None
, else returns self.tzinfo.utcoffset(self)
, and raises an exception if the latter doesn’t return None
, or a timedelta
object representing a whole number of minutes with magnitude less than one day.
datetime.dst()
If tzinfo
is None
, returns None
, else returns self.tzinfo.dst(self)
, and raises an exception if the latter doesn’t return None
, or a timedelta
object representing a whole number of minutes with magnitude less than one day.
datetime.tzname()
If tzinfo
is None
, returns None
, else returns self.tzinfo.tzname(self)
, raises an exception if the latter doesn’t return None
or a string object,
datetime.timetuple()
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
.
datetime.utctimetuple()
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 the result’s tm_year
member may be MINYEAR
-1 or MAXYEAR
+1, if d.year was MINYEAR
or MAXYEAR
and UTC adjustment spills over a year boundary.
datetime.toordinal()
Return the proleptic Gregorian ordinal of the date. The same as self.date().toordinal()
.
datetime.weekday()
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()
.
datetime.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()
.
datetime.isocalendar()
Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The same as self.date().isocalendar()
.
datetime.isoformat([sep])
Return a string representing the date and time in ISO 8601 format, YYYY-MM-DDTHH:MM:SS.mmmmmm or, if microsecond
is 0, YYYY-MM-DDTHH:MM:SS
If utcoffset()
does not return None
, a 6-character string is appended, giving the UTC offset in (signed) hours and minutes: YYYY-MM-DDTHH:MM:SS.mmmmmm+HH:MM or, if microsecond
is 0 YYYY-MM-DDTHH:MM:SS+HH:MM
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): ... def utcoffset(self, dt): return timedelta(minutes=-399) ... >>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ') '2002-12-25 00:00:00-06:39'
datetime.__str__()
For a datetime
instance d, str(d)
is equivalent to d.isoformat(' ')
.
datetime.ctime()
Return a string representing the date and time, for example datetime(2002, 12,
4, 20, 30, 40).ctime() == 'Wed Dec 4 20:30:40 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 datetime.ctime()
does not invoke) conforms to the C standard.
datetime.strftime(format)
Return a string representing the date and time, controlled by an explicit format string. For a complete list of formatting directives, see section strftime() and strptime() Behavior.
datetime.__format__(format)
Same as datetime.strftime()
. This makes it possible to specify a format string for a datetime
object when using str.format()
. See section strftime() and strptime() Behavior.
Examples of working with datetime objects:
>>> from datetime import datetime, date, time >>> # 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() or datetime.utcnow() >>> datetime.now() datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1 >>> datetime.utcnow() datetime.datetime(2007, 12, 6, 15, 29, 43, 79060) >>> # 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 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.'
Using datetime with tzinfo:
>>> from datetime import timedelta, datetime, tzinfo >>> class GMT1(tzinfo): ... def utcoffset(self, dt): ... return timedelta(hours=1) + self.dst(dt) ... def dst(self, dt): ... # DST starts last Sunday in March ... d = datetime(dt.year, 4, 1) # ends last Sunday in October ... self.dston = d - timedelta(days=d.weekday() + 1) ... d = datetime(dt.year, 11, 1) ... self.dstoff = d - timedelta(days=d.weekday() + 1) ... if self.dston <= dt.replace(tzinfo=None) < self.dstoff: ... return timedelta(hours=1) ... else: ... return timedelta(0) ... def tzname(self,dt): ... return "GMT +1" ... >>> class GMT2(tzinfo): ... def utcoffset(self, dt): ... return timedelta(hours=2) + self.dst(dt) ... def dst(self, dt): ... d = datetime(dt.year, 4, 1) ... self.dston = d - timedelta(days=d.weekday() + 1) ... d = datetime(dt.year, 11, 1) ... self.dstoff = d - timedelta(days=d.weekday() + 1) ... if self.dston <= dt.replace(tzinfo=None) < self.dstoff: ... return timedelta(hours=1) ... else: ... return timedelta(0) ... def tzname(self,dt): ... return "GMT +2" ... >>> gmt1 = GMT1() >>> # Daylight Saving Time >>> dt1 = datetime(2006, 11, 21, 16, 30, tzinfo=gmt1) >>> dt1.dst() datetime.timedelta(0) >>> dt1.utcoffset() datetime.timedelta(0, 3600) >>> dt2 = datetime(2006, 6, 14, 13, 0, tzinfo=gmt1) >>> dt2.dst() datetime.timedelta(0, 3600) >>> dt2.utcoffset() datetime.timedelta(0, 7200) >>> # Convert datetime to another time zone >>> dt3 = dt2.astimezone(GMT2()) >>> dt3 # doctest: +ELLIPSIS datetime.datetime(2006, 6, 14, 14, 0, tzinfo=<GMT2 object at 0x...>) >>> dt2 # doctest: +ELLIPSIS datetime.datetime(2006, 6, 14, 13, 0, tzinfo=<GMT1 object at 0x...>) >>> dt2.utctimetuple() == dt3.utctimetuple() True
A time object represents a (local) time of day, independent of any particular day, and subject to adjustment via a tzinfo
object.
class datetime.time([hour[, minute[, second[, microsecond[, tzinfo]]]]])
All arguments are optional. tzinfo may be None
, or an instance of a tzinfo
subclass. The remaining arguments may be ints or longs, in the following ranges:
0 <= hour < 24
0 <= minute < 60
0 <= second < 60
0 <= microsecond < 1000000
.If an argument outside those ranges is given, ValueError
is raised. All default to 0
except tzinfo, which defaults to None
.
Class attributes:
time.min
The earliest representable time
, time(0, 0, 0, 0)
.
time.max
The latest representable time
, time(23, 59, 59, 999999)
.
time.resolution
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):
time.hour
In range(24)
.
time.minute
In range(60)
.
time.second
In range(60)
.
time.microsecond
In range(1000000)
.
time.tzinfo
The object passed as the tzinfo argument to the time
constructor, or None
if none was passed.
Supported operations:
time
to time
, where a is considered less than b when a precedes b in time. If one comparand is naive and the other is aware, TypeError
is raised. If both comparands are aware, and have the same tzinfo
attribute, the common tzinfo
attribute is 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()
). In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a time
object is compared to an object of a different type, TypeError
is raised unless the comparison is ==
or !=
. The latter cases return False
or True
, respectively.time
object is considered to be true if and only if, after converting it to minutes and subtracting utcoffset()
(or 0
if that’s None
), the result is non-zero.Instance methods:
time.replace([hour[, minute[, second[, microsecond[, tzinfo]]]]])
Return a time
with the same value, except for those attributes given new values by whichever keyword arguments are specified. Note that tzinfo=None
can be specified to create a naive time
from an aware time
, without conversion of the time data.
time.isoformat()
Return a string representing the time in ISO 8601 format, HH:MM:SS.mmmmmm or, if self.microsecond is 0, HH:MM:SS If utcoffset()
does not return None
, a 6-character string is appended, giving the UTC offset in (signed) hours and minutes: HH:MM:SS.mmmmmm+HH:MM or, if self.microsecond is 0, HH:MM:SS+HH:MM
time.__str__()
For a time t, str(t)
is equivalent to t.isoformat()
.
time.strftime(format)
Return a string representing the time, controlled by an explicit format string. For a complete list of formatting directives, see section strftime() and strptime() Behavior.
time.__format__(format)
Same as time.strftime()
. This makes it possible to specify a format string for a time
object when using str.format()
. See section strftime() and strptime() Behavior.
time.utcoffset()
If tzinfo
is None
, returns None
, else returns self.tzinfo.utcoffset(None)
, and raises an exception if the latter doesn’t return None
or a timedelta
object representing a whole number of minutes with magnitude less than one day.
time.dst()
If tzinfo
is None
, returns None
, else returns self.tzinfo.dst(None)
, and raises an exception if the latter doesn’t return None
, or a timedelta
object representing a whole number of minutes with magnitude less than one day.
time.tzname()
If tzinfo
is None
, returns None
, else returns self.tzinfo.tzname(None)
, or raises an exception if the latter doesn’t return None
or a string object.
Example:
>>> from datetime import time, tzinfo, timedelta >>> class GMT1(tzinfo): ... def utcoffset(self, dt): ... return timedelta(hours=1) ... def dst(self, dt): ... return timedelta(0) ... def tzname(self,dt): ... return "Europe/Prague" ... >>> t = time(12, 10, 30, tzinfo=GMT1()) >>> t # doctest: +ELLIPSIS datetime.time(12, 10, 30, tzinfo=<GMT1 object at 0x...>) >>> gmt = GMT1() >>> t.isoformat() '12:10:30+01:00' >>> t.dst() datetime.timedelta(0) >>> t.tzname() 'Europe/Prague' >>> t.strftime("%H:%M:%S %Z") '12:10:30 Europe/Prague' >>> 'The {} is {:%H:%M}.'.format("time", t) 'The time is 12:10.'
class datetime.tzinfo
This is an abstract base class, meaning that this class should not be instantiated directly. 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 does not supply any concrete subclasses of tzinfo
.
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.
Special requirement for pickling: A tzinfo
subclass must have an __init__()
method that can be called with no arguments, else 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.
tzinfo.utcoffset(self, dt)
Return offset of local time from UTC, in minutes east of UTC. If local time is west of UTC, this should be negative. Note that this is intended to be 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 isn’t known, return None
. Else the value returned must be a timedelta
object specifying a whole number of minutes in the range -1439 to 1439 inclusive (1440 = 24*60; 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
.
tzinfo.dst(self, dt)
Return the daylight saving time (DST) adjustment, in minutes east of UTC, or None
if DST information isn’t 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 there’s no need to consult dst()
unless you’re interested in obtaining DST info separately. For example, datetime.timetuple()
calls its tzinfo
attribute’s 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 zone’s “standard offset”, 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; it’s the programmer’s 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. Then if dston <= dt.replace(tzinfo=None) < dstoff: return timedelta(hours=1) else: return timedelta(0)
The default implementation of dst()
raises NotImplementedError
.
tzinfo.tzname(self, dt)
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 there’s 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 isn’t 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
subclass’s methods should therefore be prepared to accept a dt argument of None
, or of class datetime
.
When None
is passed, it’s 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 don’t 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 timezones.
There is one more tzinfo
method that a subclass may wish to override:
tzinfo.fromutc(self, dt)
This is called from the default datetime.astimezone()
implementation. When called from that, dt.tzinfo
is self, and dt’s 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 self’s local time.
Most tzinfo
subclasses should be able to inherit the default fromutc()
implementation without problems. It’s 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
Example tzinfo
classes:
from datetime import tzinfo, timedelta, datetime ZERO = timedelta(0) HOUR = timedelta(hours=1) # A UTC class. class UTC(tzinfo): """UTC""" def utcoffset(self, dt): return ZERO def tzname(self, dt): return "UTC" def dst(self, dt): return ZERO utc = UTC() # A class building tzinfo objects for fixed-offset time zones. # Note that FixedOffset(0, "UTC") is a different way to build a # UTC tzinfo object. class FixedOffset(tzinfo): """Fixed offset in minutes east from UTC.""" def __init__(self, offset, name): self.__offset = timedelta(minutes = offset) self.__name = name def utcoffset(self, dt): return self.__offset def tzname(self, dt): return self.__name def dst(self, dt): return ZERO # A class capturing the platform's idea of local time. 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 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 # http://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; 1am standard time) on the first Sunday of Nov. DSTEND_2007 = datetime(1, 11, 1, 1) # 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; 1am standard 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, 1) # 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; # 1am standard 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 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 # Find start and end times for US DST. For years before 1967, return # ZERO for no DST. if 2006 < dt.year: dststart, dstend = DSTSTART_2007, DSTEND_2007 elif 1986 < dt.year < 2007: dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006 elif 1966 < dt.year < 1987: dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986 else: return ZERO start = first_sunday_on_or_after(dststart.replace(year=dt.year)) end = first_sunday_on_or_after(dstend.replace(year=dt.year)) # Can't compare naive to aware objects, so strip the timezone from # dt first. if start <= dt.replace(tzinfo=None) < end: return HOUR else: return ZERO 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 “start” line), the local wall clock leaps from 1:59 to 3:00. A wall time of the form 2:MM doesn’t really make sense on that day, so astimezone(Eastern)
won’t deliver a result with hour == 2
on the day DST begins. In order for astimezone()
to make this guarantee, the rzinfo.dst()
method must consider times in the “missing hour” (2:MM for Eastern) to be in daylight time.
When DST ends (the “end” line), there’s a potentially worse problem: there’s an hour that can’t be spelled unambiguously in local wall time: the last hour of daylight time. In Eastern, that’s 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 clock’s 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. In order for astimezone()
to make this guarantee, the tzinfo.dst()
method must consider times in the “repeated hour” to be in standard time. This is easily arranged, as in the example, by expressing DST switch times in the time zone’s standard local time.
Applications that can’t bear such ambiguities should avoid using hybrid tzinfo
subclasses; there are no ambiguities when using UTC, 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
The standard library has no tzinfo
instances, but there exists a third-party library which brings the IANA timezone database (also known as the Olson database) to Python: pytz.
pytz contains up-to-date information and its usage is recommended.
The Time Zone Database (often called tz 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.
strftime()
and strptime()
Behaviordate
, 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. Broadly speaking, d.strftime(fmt)
acts like the time
module’s time.strftime(fmt, d.timetuple())
although not all objects support a timetuple()
method.
Conversely, the datetime.strptime()
class method creates a datetime
object from a string representing a date and time and a corresponding format string. 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 timezone 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 they’re 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 they’re used anyway, 0
is substituted for them.
The full set of format codes supported varies across platforms, because Python calls the platform C library’s strftime()
function, and platform variations are common. To see the full set of format codes supported on your platform, consult the strftime(3) documentation.
For the same reason, handling of format strings containing Unicode code points that can’t 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.
The following is a list of all the format codes that the C standard (1989 version) requires, and these work on all platforms with a standard C implementation. Note that the 1999 version of the C standard added additional format codes.
The exact range of years for which strftime()
works also varies across platforms. Regardless of platform, years before 1900 cannot be used.
Directive | Meaning | Example | Notes |
---|---|---|---|
| Weekday as locale’s abbreviated name. | (1) | |
| Weekday as locale’s full name. | (1) | |
| Weekday as a decimal number, where 0 is Sunday and 6 is Saturday. | 0, 1, …, 6 | |
| Day of the month as a zero-padded decimal number. | 01, 02, …, 31 | |
| Month as locale’s abbreviated name. | (1) | |
| Month as locale’s full name. | (1) | |
| Month as a zero-padded decimal number. | 01, 02, …, 12 | |
| Year without century as a zero-padded decimal number. | 00, 01, …, 99 | |
| Year with century as a decimal number. | 1970, 1988, 2001, 2013 | |
| Hour (24-hour clock) as a zero-padded decimal number. | 00, 01, …, 23 | |
| Hour (12-hour clock) as a zero-padded decimal number. | 01, 02, …, 12 | |
| Locale’s equivalent of either AM or PM. | (1), (2) | |
| Minute as a zero-padded decimal number. | 00, 01, …, 59 | |
| Second as a zero-padded decimal number. | 00, 01, …, 59 | (3) |
| Microsecond as a decimal number, zero-padded on the left. | 000000, 000001, …, 999999 | (4) |
| UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive). | (empty), +0000, -0400, +1030 | (5) |
| Time zone name (empty string if the object is naive). | (empty), UTC, EST, CST | |
| Day of the year as a zero-padded decimal number. | 001, 002, …, 366 | |
| 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, …, 53 | (6) |
| Week number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0. | 00, 01, …, 53 | (6) |
| Locale’s appropriate date and time representation. | (1) | |
| Locale’s appropriate date representation. | (1) | |
| Locale’s appropriate time representation. | (1) | |
| A literal | % |
Notes:
ja_JP
, the default encoding could be any one of eucJP
, SJIS
, or utf-8
; use locale.getlocale()
to determine the current locale’s encoding).strptime()
method, the %p
directive only affects the output hour field if the %I
directive is used to parse the hour.time
module, the datetime
module does not support leap seconds.%f
is an extension to the set of format characters in the C standard (but implemented separately in datetime objects, and therefore always available). When used with the strptime()
method, the %f
directive accepts from one to six digits and zero pads on the right.
New in version 2.6.
For a naive object, the %z
and %Z
format codes are replaced by empty strings.
For an aware object:
%z
utcoffset()
is transformed into a 5-character string of the form +HHMM or -HHMM, where HH is a 2-digit string giving the number of UTC offset hours, and MM is a 2-digit string giving the number of UTC offset minutes. For example, if utcoffset()
returns timedelta(hours=-3, minutes=-30)
, %z
is replaced with the string '-0330'
.
%Z
If tzname()
returns None
, %Z
is replaced by an empty string. Otherwise %Z
is replaced by the returned value, which must be a string.
strptime()
method, %U
and %W
are only used in calculations when the day of the week and the year are specified.1
If, that is, we ignore the effects of Relativity
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Licensed under the PSF License.
https://docs.python.org/2.7/library/datetime.html