"Sun, 15 Feb 1970 14:12:03"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
14:12:03
General datetime
1970-02-15 14:12:03Z
For Database
1970-02-15 14:12:03
For HTTP1.1
Sun, 15 Feb 1970 14:12:03 GMT