"Sun, 18 Jan 1970 14:11:56"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
14:11:56
General datetime
1970-01-18 14:11:56Z
For Database
1970-01-18 14:11:56
For HTTP1.1
Sun, 18 Jan 1970 14:11:56 GMT