"Wed, 21 Jan 1970 04:42:03"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
04:42:03
General datetime
1970-01-21 04:42:03Z
For Database
1970-01-21 04:42:03
For HTTP1.1
Wed, 21 Jan 1970 04:42:03 GMT