"Sun, 15 Feb 1970 00:19:35"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
00:19:35
General datetime
1970-02-15 00:19:35Z
For Database
1970-02-15 00:19:35
For HTTP1.1
Sun, 15 Feb 1970 00:19:35 GMT