"Sun, 15 Feb 1970 21:42:15"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
21:42:15
General datetime
1970-02-15 21:42:15Z
For Database
1970-02-15 21:42:15
For HTTP1.1
Sun, 15 Feb 1970 21:42:15 GMT