"Fri, 23 Jan 1970 18:15:37"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700123
Only TIME
18:15:37
General datetime
1970-01-23 18:15:37Z
For Database
1970-01-23 18:15:37
For HTTP1.1
Fri, 23 Jan 1970 18:15:37 GMT