"Sat, 17 Jan 1970 14:56:40"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
14:56:40
General datetime
1970-01-17 14:56:40Z
For Database
1970-01-17 14:56:40
For HTTP1.1
Sat, 17 Jan 1970 14:56:40 GMT