"Mon, 12 Jan 1970 21:12:37"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700112
Only TIME
21:12:37
General datetime
1970-01-12 21:12:37Z
For Database
1970-01-12 21:12:37
For HTTP1.1
Mon, 12 Jan 1970 21:12:37 GMT