"Sun, 04 Jan 1970 19:40:03"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700104
Only TIME
19:40:03
General datetime
1970-01-04 19:40:03Z
For Database
1970-01-04 19:40:03
For HTTP1.1
Sun, 04 Jan 1970 19:40:03 GMT