"Fri, 02 Jan 1970 21:38:56"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700102
Only TIME
21:38:56
General datetime
1970-01-02 21:38:56Z
For Database
1970-01-02 21:38:56
For HTTP1.1
Fri, 02 Jan 1970 21:38:56 GMT