You choose a date and advise your staff a drill will take place on that date but don’t tell them the time of the drill. Parents are advised that a large-scale drill will take place but we do not give them the time and we post signboards in front of the school saying “School safety drill in progress.” Once confronted, the drill is over and you can conduct your “end of drill” procedure to notify everyone that the drill is over and to reopen their classrooms.