"Sun, 04 Jan 1970 18:03:38"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700104
Only TIME
18:03:38
General datetime
1970-01-04 18:03:38Z
For Database
1970-01-04 18:03:38
For HTTP1.1
Sun, 04 Jan 1970 18:03:38 GMT