Or simply have the quest giver disappear, and keep Ares around until he dies. It's not that difficult, since he's in an instance. If he spawns BEFORE 2200 server time, but 2200 comes around BEFORE he dies, it shouldnt be difficult to have the NPC that gives the quest disappear, but keep the active instance viable until he dies, and reward NPC despawns. I'm not a coding expert, but since it's a custom event, altering the coding to make the termination time open ended shouldnt be all that difficult.