chrisonline Yes I mean no conversion shall to be done, Because Iran calendar is different than Gregorian Calendar as the examples I said.
Note: the picker library is also old and not the perfect one, Because Esfand 1403 has 30 days while the date picker shows only 29 days (this is not related to this issue anyway).
https://github.com/razaghimahdi/Compose-Persian-Date-Picker
the above might be a better alternative if it fits your project
I am a programmer myself (not android/java though), to solve the issue I have, ColReminder needs to store the Iranian date if it was chosen via Iran date picker instead of Gregorian date, then upon each check of reminder, it should match the date and the repetition of it with the current time converted to Iran date and time, if they matched then it should remind