"Tue, 20 Jan 1970 00:18:47"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
00:18:47
General datetime
1970-01-20 00:18:47Z
For Database
1970-01-20 00:18:47
For HTTP1.1
Tue, 20 Jan 1970 00:18:47 GMT