You're highlighting the perverseness of time management. At its best it's a giant confusing mess, and that's before we get to all the bizarre business logic that's built up over time.

I actually think it may simply be that we have signs and large printed things with times on them, and it'd be onerous to have to replace each multiple times a year (or make them bigger with a layer of conditionals based on date). Instead, we push that complexity onto the backend and deal with time there. It's certainly easier from the customer and business owner, and we've merely make life much more difficult for the programmers and engineers... which is probably how it should be. It's the job of the technical people to deal with the technicalities, so to me, it seems like everything is working properly.

Still a nasty, messy problem, though.