Get rid of eorzea time and just use real time

[Jynx]

Actually, it does. If you switch to real life time and decide to still implement events around specific times of day, you're shooting yourself in the foot

Again, what is to stop them from just making some monsters spawn every hour and then not spawn the next?

Nothing, gametime has nothing to do with such "Inconvient" methods. It's just something to base the idea of something like the undead coming out at night. Not alot of people like looking at Skeletons in a sunny field of flowers.