"Wed, 21 Jan 1970 23:38:50"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
23:38:50
General datetime
1970-01-21 23:38:50Z
For Database
1970-01-21 23:38:50
For HTTP1.1
Wed, 21 Jan 1970 23:38:50 GMT