"Sat, 17 Jan 1970 21:48:52"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
21:48:52
General datetime
1970-01-17 21:48:52Z
For Database
1970-01-17 21:48:52
For HTTP1.1
Sat, 17 Jan 1970 21:48:52 GMT