"Sun, 01 Feb 1970 04:42:36"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700201
Only TIME
04:42:36
General datetime
1970-02-01 04:42:36Z
For Database
1970-02-01 04:42:36
For HTTP1.1
Sun, 01 Feb 1970 04:42:36 GMT