"Wed, 18 Feb 1970 14:45:20"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700218
Only TIME
14:45:20
General datetime
1970-02-18 14:45:20Z
For Database
1970-02-18 14:45:20
For HTTP1.1
Wed, 18 Feb 1970 14:45:20 GMT