Q. Which calendar do certain Eastern Orthodox churches follow, leading to Christmas being celebrated on January 7th?
Answer:
Julian Calendar
Notes: Certain Eastern Orthodox churches, including Russian and other traditions, observe Christmas on January 7th due to their adherence to the ancient Julian calendar. This calendar runs 13 days behind the widely-used Gregorian calendar, causing the date of December 25th in the Julian calendar to fall on January 7th in the Gregorian calendar.