keeping a zone depoped for about 3 hours or so

[Darkheat]

I am writing an event in crush bone where the elves take over crush bone in the process I need to depop the zone for two or three hours but I notice that the quest::depop() will only depop the zone until the spawn timers are up. Is there any way to keep all the mobs in the zone depopped until the repop command is used or the 3 hours is up?

If not what would be the best way to go about achieving this goal?

Thanks in advance