The date in 1452 was 11 March, 11:52 (Julian). In 2547 it will be 20 March, 21:18 (Gregorian) and 3 March, 21:18 (Julian). Western Christendom In Western Christendom, the March equinox is one of the factors used to determine the date of Easter. However, the Gregorian reform of the calendar declared 21 March to be the date for the ecclesiastical equinox, and it is this fixed date (rather than the date of the actual astronomical event) that is used for the Easter date calculation. Commemorations Abrahamic tradition The Jewish Passover usually falls on the first full moon after the northern hemisphere vernal equinox, although occasionally (currently three times every 19 years) it will occur on the second full moon. The Christian Churches calculate Easter as the first Sunday after the first full moon on or after the March equinox. The official church definition for the equinox is 21 March. The Eastern Orthodox Churches use the older Julian calendar, while the western churches use the Gregorian calendar, and the western full moons currently fall four, five or 34 days before the eastern ones. The result is that the two Easters generally fall on different days but they sometimes coincide. The earliest possible western Easter date in any year is 22 March on each calendar. The latest possible western Easter date in any year is 25 April. Iranian tradition The northward equinox marks the first day of various calendars including the Iranian calendar. The ancient Iranian peoples' new year's festival of Nowruz can be celebrated 20 March or 21 March. According to the ancient Persian mythology Jamshid, the mythological king of Persia, ascended to the throne on this day and each year this is commemorated with festivities for two weeks. Along with Iranian peoples, it is also a holiday celebrated by Turkic people, the North Caucasus and in Albania. It is also a holiday for Zoroastrians, adherents of the Baháʼí Faith and Nizari Ismaili Muslims irrespective of ethnicity. West Asia and North Africa In many Arab countries, Mother's Day is celebrated on the northward equinox. Sham el-Nessim was an ancient Egyptian holiday which can be traced back as far as 2700 BC. It is still one of the public holidays in Egypt. Sometime during Egypt's Christian period (c. 200–639) the date moved to Easter Monday, but before then it coincided with the vernal equinox. South and Southeast Asia According to the sidereal