"Mon, 19 Jan 1970 18:14:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700119
Only TIME
18:14:21
General datetime
1970-01-19 18:14:21Z
For Database
1970-01-19 18:14:21
For HTTP1.1
Mon, 19 Jan 1970 18:14:21 GMT