Datetime

Datetime representation

Code

import datetime

Create

Action	Code	Details
From ymdhms	datetime(year, month, day, hour, minute, second)
Current datetime	datetime.now()
Current datetime in UTC timezone	datetime.utcnow()
Unix epoch	datetime.fromtimestamp(0)
From date and time	datetime.combine(date, time)
Datetime from any valid ISO 8601 datetime string	datetime.fromisoformat(datetime_str)	e.g. 2023-01-30 23:59, 2023-01-30T23:59:01
Datetime from YYYY-MM-DD HH:mm:ss	x.strptime('%y-%m-%d %H:%M:%S')
Datetime from string (unknown format)	pandas.to_datetime('2023 Jan 5')	uses the pandas package
From total seconds since Unix epoch	datetime.fromtimestamp(n)
From total seconds since reference datetime	ref_datetime + timedelta(seconds=n)
From total days since Unix epoch	datetime.fromtimestamp(0) + timedelta(n)
From total days since reference datetime	ref_datetime + timedelta(n)

Constants

Action	Code	Details
Earliest representable datetime	datetime.min
Latest representable datetime	datetime.max

Test

Action	Code	Details
Is datetime	isinstance(x, datetime.datetime)
Same moment	x == y	Up to x.resolution precision (usually 1μs)
Happens before y	x < y
Happens after y	x > y

Extract

Action	Code	Details
Year	x.year
Month	x.month
Day	x.day
Hour	x.hour
Minute	x.minute
Second	x.second
Microsecond	x.microsecond
Weekday number	x.isoweekday()	Mon=1, Sun=7
Weekday number (zero-based)	x.weekday()	Mon=0, Sun=6

Derive

Action	Code	Details
Change to first day of year	x.replace(month=1, day=1)
Change to first day of month	x.replace(day=1)
Change year to y	x.replace(year=y)
In UTC timezone	?
Shift forward by n days	x + timedelta(days=n)
Shift forward by n seconds	x + timedelta(seconds=n)

Convert

Action	Code	Details
Date component	x.date()
Time component	x.time()
Timestamp (seconds from Unix epoch), as float	x.timestamp()
Format datetime as ISO 8601	x.isoformat()	e.g., 2023-01-01T23:59:00
Format readable datetime of consistent length	x.ctime()	e.g., Sun Jan 1 23:59:00 2023
Format datetime as YYYY-MM-DD	x.date().isoformat()	e.g., 2024-01-31
Format datetime as DD-MMM-YYYY	x.strftime('%d-%b-%Y')	e.g., 31-Jan-2023
Format datetime as HH:mm	x.strftime('%H:%M')	e.g., 23:59
Format datetime as HH:mm:ss	x.strftime('%H:%M:%S')	e.g., 23:59:00
Format datetime as YYYY-MM-DD HH:mm:ss	x.strftime('%y-%m-%d %H:%M:%S')
Named tuple	x.timetuple()