"Sat, 17 Jan 1970 20:42:23"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
20:42:23
General datetime
1970-01-17 20:42:23Z
For Database
1970-01-17 20:42:23
For HTTP1.1
Sat, 17 Jan 1970 20:42:23 GMT