How to change the calendar default type to islamic or persian calendar?

Greetings,

I have a problem with changing the calendar to persian or islamic type, I tried the appearance code ( persian , myanmar , persian* , myanmar* ) but this change not working on the default calendar also from the XLSform editoin.
Please help me fix the problem.

Welcome to the community, @Besmallaharya! You could do this as outlined in this post discussed previously:

You should be able to learn more about the Islamic date format here and the Persian date format here.