"Sat, 17 Jan 1970 21:48:56"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
21:48:56
General datetime
1970-01-17 21:48:56Z
For Database
1970-01-17 21:48:56
For HTTP1.1
Sat, 17 Jan 1970 21:48:56 GMT