"Sun, 15 Feb 1970 18:24:55"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
18:24:55
General datetime
1970-02-15 18:24:55Z
For Database
1970-02-15 18:24:55
For HTTP1.1
Sun, 15 Feb 1970 18:24:55 GMT