"Sun, 04 Jan 1970 12:38:18"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700104
Only TIME
12:38:18
General datetime
1970-01-04 12:38:18Z
For Database
1970-01-04 12:38:18
For HTTP1.1
Sun, 04 Jan 1970 12:38:18 GMT