Thrust Day.
On the first day of every new flight school and A&P class, at every campus, everything stops. It is part welcome for the people starting and part pinning ceremony for the people who have passed a checkride since the last one.
The pinning is the point. Certificates arrive as a piece of paper in the post weeks later, which is a strange way to mark the hardest thing you have done all year. This way the room you have been struggling in front of watches you get it.
Around it there are cookouts, game nights and aviation competitions of varying seriousness. None of it is compulsory and most people come anyway.