"Sat, 31 Jan 1970 00:20:27"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700131
Only TIME
00:20:27
General datetime
1970-01-31 00:20:27Z
For Database
1970-01-31 00:20:27
For HTTP1.1
Sat, 31 Jan 1970 00:20:27 GMT