Allow command usage on specified times

Hello.
I cant think a way to make a way, that will prevent peoples from using commands. I need that they can use the text command only from 16:00 till 22:00, how to do that?

Code:

if ($time(HH) >= 16) && ($time(HH) < 22)

Code:

if ($time(HH) isnum 16-21) <do stuff>

Silly hixxy. ;P I thought about doing that an hour or so after I posted, but couldn't be bothered to change my post since I figured he wouldn't see it anymore.