an Eastern Orthodox Church body which uses the historic Julian calendar (“Old Calendar”), and whose Church body is not in communion with the Eastern Orthodox Churches that use the New Calendar
Old Calendarists is the name for two groups of Eastern Orthodox churches:
- Some churches have always used the Julian calendar to determine holidays and church festivities. This means that from 1900 to about 2100, the date of a given occasion is about thirteen days later, than if the Gregorian calendar had been used.
- Some churches (and splinter groups) have switched back from the new calendar to the old one in the 20th century.
In addition, other Christian churches use the Julian Calendar: