"Tue, 20 Jan 1970 23:38:42"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
23:38:42
General datetime
1970-01-20 23:38:42Z
For Database
1970-01-20 23:38:42
For HTTP1.1
Tue, 20 Jan 1970 23:38:42 GMT