"Sun, 18 Jan 1970 19:40:54"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
19:40:54
General datetime
1970-01-18 19:40:54Z
For Database
1970-01-18 19:40:54
For HTTP1.1
Sun, 18 Jan 1970 19:40:54 GMT