"Sat, 17 Jan 1970 23:38:50"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700117
Only TIME
23:38:50
General datetime
1970-01-17 23:38:50Z
For Database
1970-01-17 23:38:50
For HTTP1.1
Sat, 17 Jan 1970 23:38:50 GMT