"Sat, 03 Jan 1970 18:16:38"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
18:16:38
General datetime
1970-01-03 18:16:38Z
For Database
1970-01-03 18:16:38
For HTTP1.1
Sat, 03 Jan 1970 18:16:38 GMT