The intercultural calendar of the Federal Office for Migration and Refugees shows the variety of holidays and memorial days of different religions and cultures that live together in Germany. Therefore, in addition to the most important holidays from Christianity, Judaism, Islam, Hinduism, the Sikhs and Yazidis, the Intercultural Calendar also includes legal and other observances of various cultural traditions www.bamf.de/SharedDocs/Anlagen/DE/Downloads/Infothek/Sonstige/interkultureller-kalender-2018.
In the federal states there is the possibility to get exemption from school for high holidays of various religions.
Pupils in the state of Hamburg get school-free for special religious holidays of the respective religious communities. The religious holidays are listed here: http://www.hamburg.de/contentblob/3031278/371a457029abb5dd0b9ee02de85531b8/data/feiertage.pdf