"Tue, 20 Jan 1970 04:38:38"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
04:38:38
General datetime
1970-01-20 04:38:38Z
For Database
1970-01-20 04:38:38
For HTTP1.1
Tue, 20 Jan 1970 04:38:38 GMT