"Wed, 21 Jan 1970 15:20:47"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
15:20:47
General datetime
1970-01-21 15:20:47Z
For Database
1970-01-21 15:20:47
For HTTP1.1
Wed, 21 Jan 1970 15:20:47 GMT