"Tue, 20 Jan 1970 23:38:03"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
23:38:03
General datetime
1970-01-20 23:38:03Z
For Database
1970-01-20 23:38:03
For HTTP1.1
Tue, 20 Jan 1970 23:38:03 GMT