"Wed, 21 Jan 1970 18:16:13"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
18:16:13
General datetime
1970-01-21 18:16:13Z
For Database
1970-01-21 18:16:13
For HTTP1.1
Wed, 21 Jan 1970 18:16:13 GMT