"Tue, 20 Jan 1970 19:40:37"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
19:40:37
General datetime
1970-01-20 19:40:37Z
For Database
1970-01-20 19:40:37
For HTTP1.1
Tue, 20 Jan 1970 19:40:37 GMT