Anyone who’s lived in Japan will know that they have many, many national holidays. The autumn and spring equinoxes are national holidays too.
Japanese people seem to really like acknowledging the changing of the seasons. Restaurant menus (even cheap places) will have autumn-themed menus with pumpkin, chestnuts and mushrooms, and many people enjoy going to parks to admire the autumn leaves. It’s also common for schools to have sports day in autumn, probably because it’s impossibly hot in summer.