"Tue, 20 Jan 1970 00:40:23"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
00:40:23
General datetime
1970-01-20 00:40:23Z
For Database
1970-01-20 00:40:23
For HTTP1.1
Tue, 20 Jan 1970 00:40:23 GMT