"Sat, 03 Jan 1970 00:40:13"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
00:40:13
General datetime
1970-01-03 00:40:13Z
For Database
1970-01-03 00:40:13
For HTTP1.1
Sat, 03 Jan 1970 00:40:13 GMT