It's Azlier's DayNightEvent, so just ask him to update it. If he doesn't want to, that's his decision, but I want his thoughts on this. Personally, I don't like it.
1. Useless to declare a local unit.
2. You null that but not the trigger (nulling the trigger will be nice)
3. WorldBounds... why not use SetUnitPosition(100000, 100000)?
4. EVENT_DAY() and EVENT_NIGHT() is sloppy. Use GetDayEvent() or GetNightEvent() instead so it's not spaghetti code.
5. Again, just ask Azlier to update his.