"Sun, 04 Jan 1970 20:39:47"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700104
Only TIME
20:39:47
General datetime
1970-01-04 20:39:47Z
For Database
1970-01-04 20:39:47
For HTTP1.1
Sun, 04 Jan 1970 20:39:47 GMT