"Tue, 20 Jan 1970 18:03:44"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
18:03:44
General datetime
1970-01-20 18:03:44Z
For Database
1970-01-20 18:03:44
For HTTP1.1
Tue, 20 Jan 1970 18:03:44 GMT