When the Zombie Massacre map maker/SDK is released, it would be really cool to have the option to set player spawns and zombie spawns on a per day basis.
This would allow for multi-stage type maps to be created, where each day is a different area.
Even outside of this, having different spawns per day can make the map feel more dynamic. Being able to toggle zombie spawners with I/O would be great as well because you’d be able to make blocked areas that can be opened without having them be devoid of spawns.