"American" formats:
9/11                    4:08 pm
12/22/78                8:51:00 am

"Combined" formats:
Sat, 24 Apr 2004 21:48:40 +0200
2001-11-29T13:20:01.123-05:00

Descriptive formats:
tomorrow                last saturday
four months ago         +40 days 2 hours

Textual formats:
December 22. 1978       22-december-78

All ISO 8601 formats:
1978/12/22              1978-12-22              70-4-25
13:03:12.45678          15:57:41.0 pdt          13:03 CEST
13:03:12.45678 +0100    13:03:12.45678 CEST     04:05 -0930
15:57-8                 231431 CEST             23:41F

Database specific formats:
1999-Jan-08
1999.238