SE started the 24 Hr Maintenance since 2.4. The reason why Patch 2.4 was a 25 Hour Maintenance is because the community voiced it to SE because it was set to finish at 12am PST. This is exactly 1 hour before the weekly reset, which means getting an extra set of tomestones in before the reset. This would've let to an unfair advantage to the masses that had IRL obligations if the game went up before the Server reset. That is why all maintenances end after the reset has kicked in.