"Wed, 21 Jan 1970 18:03:31"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
18:03:31
General datetime
1970-01-21 18:03:31Z
For Database
1970-01-21 18:03:31
For HTTP1.1
Wed, 21 Jan 1970 18:03:31 GMT