"Sun, 18 Jan 1970 02:27:38"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
02:27:38
General datetime
1970-01-18 02:27:38Z
For Database
1970-01-18 02:27:38
For HTTP1.1
Sun, 18 Jan 1970 02:27:38 GMT