🇯🇵Does Japan have Other days of the Islamic calendar?

Not observed here

Japan has no Islamic holiday of any kind. The national holidays are all written into the Act on National Holidays, a closed list that can be extended only by amending the law, and Japan has no mechanism for religious holidays at local level — neither prefectures nor municipalities may add one. The days on the list are secular in framing: New Year's Day, Coming of Age Day, National Foundation Day and the like, with anything once religious rewritten under a non-religious name. So the Islamic New Year and the Prophet's birthday are marked entirely inside mosques and Muslim communities, at gatherings such as those at Tokyo Camii, with no bearing on the national calendar.