Almost all offices in Japan are open during the lunch time. Someone says post offices there are also closed at the time. Japanese office workers go out for lunch by turns and offices are open. At closing time, offices shut the entrance doors only, the windows are open.
People wait for their turn, and then go out through back doors.
Any comment is welcome. Here, our town post office is open from 8 am til 4 pm. The workers take turns going to lunch, so it is open at lunch time. In Alaska post offices have different times to be open. In Fairbanks, the airport post office is open from 9 a.m. until 9 p.m. The downtown post office closes at 6 p.m.