You can specify DATETIME, DATE, and TIMESTAMP values using any of a common set of formats:
* As a string in either 'YYYY-MM-DD HH:MM:SS' or 'YY-MM-DD HH:MM:SS' format. A ``relaxed'' syntax is allowed--any punctuation character may be used as the delimiter between date parts or time parts. For example, '98-12-31 11:30:45', '98.12.31 11+30+45', '98/12/31 11*30*45', and '98@12@31 11^30^45' are equivalent.
* As a string in either 'YYYY-MM-DD' or 'YY-MM-DD' format. A ``relaxed'' syntax is allowed here, too. For example, '98-12-31', '98.12.31', '98/12/31', and '98@12@31' are equivalent.
* As a string with no delimiters in either 'YYYYMMDDHHMMSS' or 'YYMMDDHHMMSS' format, provided that the string makes sense as a date. For example, '19970523091528' and '970523091528' are interpreted as '1997-05-23 09:15:28', but '971122129015' is illegal (it has a nonsensical minute part) and becomes '0000-00-00 00:00:00'.
* As a string with no delimiters in either 'YYYYMMDD' or 'YYMMDD' format, provided that the string makes sense as a date. For example, '19970523' and '970523' are interpreted as '1997-05-23', but '971332' is illegal (it has nonsensical month and day parts) and becomes '0000-00-00'.
* As a number in either YYYYMMDDHHMMSS or YYMMDDHHMMSS format, provided that the number makes sense as a date. For example, 19830905132800 and 830905132800 are interpreted as '1983-09-05 13:28:00'.
* As a number in either YYYYMMDD or YYMMDD format, provided that the number makes sense as a date. For example, 19830905 and 830905 are interpreted as '1983-09-05'.
* As the result of a function that returns a value that is acceptable in a DATETIME, DATE, or TIMESTAMP context, such as NOW() or CURRENT_DATE.
Illegal DATETIME, DATE, or TIMESTAMP values are converted to the ``zero'' value of the appropriate type ('0000-00-00 00:00:00', '0000-00-00', or 00000000000000).