Operations such as to_char and to_date support a limited number of format masks:
- YYYY: 4-digit year.
- YYYYMM: 4-digit year, plus 2-digit number month within year.
- YYYYMMDD: 4-digit year, 2-digit month number within year, plus 2-digit day number within month.
- YYYYMMDDHH24MI: 4-digit year, 2-digit month number within year, 2-digit day number within month, 2-digit 24-hour clock hour number, plus 2-digit minutes number within hour.
- YYYYMMDDHH24MISS: 4-digit year, 2-digit month number within year, 2-digit day number within month, 2-digit 24-hour clock hour number, 2-digit minutes number within hour, plus 2-digit seconds number within minute.
- YYYY-MM-DD: 4-digit year, dash ('-'), 2-digit month number within year, dash ('-'), plus 2-digit day number within month.
- YYYY-MM-DD HH24:MI:SS: 4-digit year, dash ('-'), 2-digit month number within year, dash ('-'), plus 2-digit day number within month, 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- YYYY/MM/DD: 4-digit year, slash ('/'), 2-digit month number within year, slash ('/'), plus 2-digit day number within month.
- YYYY/MM/DD HH24:MI:SS: 4-digit year, slash ('/'), 2-digit month number within year, slash ('/'), plus 2-digit day number within month, 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- MMDDYY: 2-digit month number within year, 2-digit day number within month, plus 2-digit year.
- MMDDYYYY: 2-digit month number within year, 2-digit day number within month, plus 4-digit year.
- DDMMYYYY: 2-digit day number within month, 2-digit month number within year, 4-digit year.
- DD-MM-YY: 2-digit day number within month, dash ('-'), 2-digit month number within year, dash ('-'), 2-digit year.
- DD-MMM-YY: 2-digit day number within month, dash ('-'), short month name, dash ('-'), 2-digit year.
- DD/MM/YY: 2-digit day number within month, slash ('/'), 2-digit month number within year, slash ('/'), 2-digit year.
- DD/MMM/YY: 2-digit day number within month, slash ('/'), short month name, slash ('/'), 2-digit year.
- DD-MM-YYYY: 2-digit day number within month, dash ('-'), 2-digit month number within year, dash ('-'), 4-digit year.
- DD-MMM-YYYY: 2-digit day number within month, dash ('-'), short month name within year, dash ('-'), 4-digit year.
- DD/MM/YYYY: 2-digit day number within month, slash ('/'), 2-digit month number within year, slash ('/'), 4-digit year.
- DD/MMM/YYYY: 2-digit day number within month, slash ('/'), short month name within year, slash ('/'), 4-digit year.
- DD-MM-YYYY HH24:MI:SS: 2-digit day number within month, dash ('-'), 2-digit month number within year, dash ('-'), 4-digit year, space (' '), 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- DD/MM/YYYY HH24:MI:SS: 2-digit day number within month, slash ('/'), 2-digit month number within year, slash ('/'), 4-digit year, space (' '), 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- MM/DD/YYYY HH24:MI:SS: 2-digit month number within year, slash ('/'), 2-digit day number within month, slash ('/'), 4-digit year, space (' '), 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- DD/MMM/YYYY HH24:MI:SS: 2-digit day number within month, slash ('/'), short month name within year, slash ('/'), 4-digit year, space (' '), 2-digit hour on 24 hour clock, colon (':'), 2-digit minutes within hour, colon (':'), 2-digit seconds within minutes.
- YYYYIW: 4-digit year, plus ISO week number.
- YYYY-IW: 4-digit year, dash ('-'), plus ISO week number.
- IW: ISO week number.
- D: day of week according to ISO 8601.
- MMMM DD, YYYY HH24:MI TT: long month, 2-digit day number within month, comma (','), space (' '), 4-digit year number, space (' '), 2-digit hour on 24 hour clock, colon (':'), 2-digit minute within hour, space (' '), time zone.