"Sun, 18 Jan 1970 21:44:12"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
21:44:12
General datetime
1970-01-18 21:44:12Z
For Database
1970-01-18 21:44:12
For HTTP1.1
Sun, 18 Jan 1970 21:44:12 GMT