The Byzantine fast is observed from November 15 to December 24, inclusively. These dates apply to the Eastern Catholic Churches, and Eastern Orthodox Churches which use the Revised Julian calendar, which currently matches the Gregorian calendar. For those Eastern Orthodox Churches which still follow the Julian calendar (Greek Orthodox Patriarchate of Jerusalem, Russian Orthodox Church, Romanian Orthodox Church, Serbian Orthodox Church, Polish Orthodox Church, Georgian Orthodox Church, Ukrainian Orthodox Church, Macedonian Orthodox Church, and Mount Athos), the Winter Lent does not begin until November 28 (Gregorian) which coincides with November 15 on the Julian calendar. The Ancient Church of the East fasts dawn til dusk from December 1 until December 25 on the Gregorian calendar.