"Sun, 11 Jan 1970 14:57:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700111
Only TIME
14:57:21
General datetime
1970-01-11 14:57:21Z
For Database
1970-01-11 14:57:21
For HTTP1.1
Sun, 11 Jan 1970 14:57:21 GMT