"Tue, 20 Jan 1970 18:12:48"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
18:12:48
General datetime
1970-01-20 18:12:48Z
For Database
1970-01-20 18:12:48
For HTTP1.1
Tue, 20 Jan 1970 18:12:48 GMT