It depends on what part of orthodox you are. IE: Greeks go by the new orthodox calendars, as do most Romainan people, and they celebrate Dec 25th like all of us. But Serbians still go by the old country calendar. I'm Romainan but my great grandmother still likes celebrating the Jan 7th Christmas. She came here on the boat and is still set on her old ways. But I don't blame her, she is 98 and why change it now lol.