"Tue, 20 Jan 1970 21:48:36"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
21:48:36
General datetime
1970-01-20 21:48:36Z
For Database
1970-01-20 21:48:36
For HTTP1.1
Tue, 20 Jan 1970 21:48:36 GMT