Date & time
Create
These assume the datetime methods have been imported. Otherwise, prefix with datetime..
| What | How | Details |
| Define date | date(year, month, day) | |
| Define time | time(hour, minute, second) | |
| Define datetime | datetime(year, month, day, hour, minute, second) | |
| Current date | datetime.now().date() | |
| Current time | datetime.now().time() | |
| Current datetime | datetime.now() | |
| Current datetime in UTC timezone | datetime.now(timezone.utc) | |
| Combine date and time | datetime.combine(date, time) | |
| Date from any valid ISO 8601 date string | date.fromisoformat(date_string) | e.g., 2023-01-30 or 20230130 |
| Time from any valid ISO 8601 time string | time.fromisoformat(time_str) | e.g. 23:59:01 |
| Datetime from any valid ISO 8601 datetime string | datetime.fromisoformat(datetime_str) | e.g. 2023-01-30 23:59, 2023-01-30T23:59:01 |
| Date from YYYY-MM-DD string | datetime.strptime(datetime_str, '%y-%m-%d') | |
| Date from DD-MMM-YYYY string | datetime.strptime(datetime_str, '%d-%b-%y') | |
| 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') | |
| Date from timestamp f (float) | date.fromtimestamp(f) | |
| What | How | 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 |
Test
| What | How | Details |
| Same moment | x == y | Up to x.resolution precision (usually 1μs) |
| Happens before y | x < y | |
| Happens after y | x > y | |
Difference
| What | How | Details |
| Difference between dates | x - y | timedelta object |
| Difference between dates, in seconds | (x - y).total_seconds() | |
| Difference between dates, in whole days | (x - y).days | |
| Difference between dates, in years | x.year - y.year - ((x.month, x.day) < (y.month, y.day)) | Source |
Derive
| What | How | 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 | datetime.now(timezone.utc) | |
| Shift forward by n days | x + timedelta(days=n) | |
| Shift forward by n seconds | x + timedelta(seconds=n) | |
| Shift forward by n days, m hours | x + timedelta(days=n, hours=m) | |
Convert
| What | How | Details |
| Timestamp (float) | x.timestamp() | |
| Named tuple of | x.timetuple() | |
| Format date as ISO 8601 | x.isoformat() | e.g., 2023-01-01 |
| Format time as ISO 8601 | x.isoformat() | e.g., 23:59:00 |
| 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., 01-Jan-2023 |
| Format datetime as DD-MMM-YYYY | x.strftime('%d-%b-%Y') | e.g., 01-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') | |