Block Posts by Time?

Hi all. I’m looking for a plugin that probably doesn’t exist, but would come in VERY handy for me.

I run a net radio station, and one of the rules of the station is the DJs must post their show notes at least 2 hours before their show. Trouble is, we have a few DJs who wait until AFTER their show starts, and then when they get called on the “no show notes” rule, quickly post the notes and say “see? there they are!”

So what I’m looking for is a way to “lock them out” of being able to post within 2 hours of their show.

Like this:

DJLazy has a show at 9pm. So, from 7pm until 10pm, he wouldn’t be able to post on the site. BEFORE 7pm, and AFTER 10pm he could post normally.

Could that be done with a plugin, or combination of plugins?

Thanks in advance!