"Sun, 15 Feb 1970 00:20:05"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
00:20:05
General datetime
1970-02-15 00:20:05Z
For Database
1970-02-15 00:20:05
For HTTP1.1
Sun, 15 Feb 1970 00:20:05 GMT