>Mount Athos never adopted the new-fangled 16th-century Gregorian calendar; they still use the Julian calendar of the Roman Empire, which lags 13 days behind R

>Mount Athos never adopted the new-fangled 16th-century Gregorian calendar; they still use the Julian calendar of the Roman Empire, which lags 13 days behind Russian Orthodox Church also still follows the Julian calendar. Majority of Orthodox countries switched to Gregorian only in the 20th century.