"Wed, 21 Jan 1970 21:46:36"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
21:46:36
General datetime
1970-01-21 21:46:36Z
For Database
1970-01-21 21:46:36
For HTTP1.1
Wed, 21 Jan 1970 21:46:36 GMT