"Tue, 06 Jan 1970 18:15:20"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700106
Only TIME
18:15:20
General datetime
1970-01-06 18:15:20Z
For Database
1970-01-06 18:15:20
For HTTP1.1
Tue, 06 Jan 1970 18:15:20 GMT