SQL
Part Specifiers Only Usable as Date Part Specifiers
| Specifier | Description | Synonyms | Example |
|:--|:--|:---|:-|
| `'dayofweek'` | Day of the week (Sunday = 0, Saturday = 6) | `'weekday'`, `'dow'` | `2` |
| `'dayofyear'` | Day of the year (1-365/366) | `'doy'` | `215` |
| `'epoch'` | Seconds since 1970-01-01 | | `1627991984` |
| `'era'` | Gregorian era (CE/AD, BCE/BC) | | `1` |
| `'isodow'` | ISO day of the week (Monday = 1, Sunday = 7) | | `2` |
| `'isoyear'` | ISO Year number (Starts on Monday of week containing Jan 4th) | | `2021` |
| `'timezone_hour'` | Time zone offset hour portion | | `0` |
| `'timezone_minute'` | Time zone offset minute portion | | `0` |
| `'timezone'` | Time zone offset in seconds | | `0` |
| `'week'` | Week number | `'weeks'`, `'w'` | `31` |
| `'yearweek'` | ISO year and week number in `YYYYWW` format | | `202131` |  
Note that the time zone parts are all zero unless a time zone plugin such as ICU
has been installed to support `TIMESTAMP WITH TIME ZONE`.