ANSWER:

Issues of takfeer must never be discussed by laymen and people without proper knowledge over issues of aqeedah as this would drive such a person to adopting the ideology of the Khawarij and would always be inclined to give takfeer to those who do not see eye to eye with him!

Legislating is the right of only Allah. Anyone who shares this with Him is committing kufr.

Using different calendars is not legislating. It can be sinful and it can be imitating the disbelievers or an innovation but never kufr.

I am actually very confused regarding geogrian calendar because we all follow normally geogrian calendar. If those who prefer maadelaw over allah’s law is guilty of kufr,then why those who prefer gegroian calendar over hijri calendar won’t be guilty of kufr? Because you told me in one of previous questions that those who actually celebrate birthdays are not guilty of kufr.