"Sun, 18 Jan 1970 02:46:48"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
02:46:48
General datetime
1970-01-18 02:46:48Z
For Database
1970-01-18 02:46:48
For HTTP1.1
Sun, 18 Jan 1970 02:46:48 GMT