"Sat, 03 Jan 1970 20:39:48"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
20:39:48
General datetime
1970-01-03 20:39:48Z
For Database
1970-01-03 20:39:48
For HTTP1.1
Sat, 03 Jan 1970 20:39:48 GMT