It's all about funding. Missed days must be made up or you lose funding. There were few snow days in the 80s so it didn't matter much, after 94 it became a problem, and after Sandy and Snowtober districts started doing away with some holidays; President's Day was a 4 day weekend for most of my career, and many schools had Feb breaks. With the violent weather the past few decades, and power outages that force closures even outside winter months, they had to limit some holidays. After Covid it became apparent you could say school was technically open even if a LOT of the kids logged on and left or didn't bother at all, but you wouldn't lose funding. Been retired for a few years now so I don't know how many hours they have to be online, I believe it's a half day schedule.