"Wed, 21 Jan 1970 15:20:48"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
15:20:48
General datetime
1970-01-21 15:20:48Z
For Database
1970-01-21 15:20:48
For HTTP1.1
Wed, 21 Jan 1970 15:20:48 GMT