"Sat, 03 Jan 1970 21:40:01"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
21:40:01
General datetime
1970-01-03 21:40:01Z
For Database
1970-01-03 21:40:01
For HTTP1.1
Sat, 03 Jan 1970 21:40:01 GMT