"Mon, 12 Jan 1970 21:47:48"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700112
Only TIME
21:47:48
General datetime
1970-01-12 21:47:48Z
For Database
1970-01-12 21:47:48
For HTTP1.1
Mon, 12 Jan 1970 21:47:48 GMT