"Sat, 03 Jan 1970 18:15:39"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
18:15:39
General datetime
1970-01-03 18:15:39Z
For Database
1970-01-03 18:15:39
For HTTP1.1
Sat, 03 Jan 1970 18:15:39 GMT