"Mon, 02 Feb 1970 00:20:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700202
Only TIME
00:20:21
General datetime
1970-02-02 00:20:21Z
For Database
1970-02-02 00:20:21
For HTTP1.1
Mon, 02 Feb 1970 00:20:21 GMT