"Sun, 18 Jan 1970 15:06:42"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
15:06:42
General datetime
1970-01-18 15:06:42Z
For Database
1970-01-18 15:06:42
For HTTP1.1
Sun, 18 Jan 1970 15:06:42 GMT