The Calculation of Pascha (“Greek” Easter and “American” Easter)
In 325 AD, after nearly three centuries of confused dates of Pascha, the 1st Ecumenical Council, held in Nicaea, came up with a plan for all Churches to use to calculate the date of Pascha, as it seemed that it was an important point for all Christians to celebrate this, the Feast of Feasts, on the same day (Remember this statement, as it will appear again, roughly 1600 years later in history). The calculation is very simple: the Sunday, which follows the first full moon after the Vernal Equinox (actual beginning of spring, 12 hours of Day and 12 hours of Night).
Many Orthodox people who try to tell you the calculation will factor in the end of Passover. Contrary to popular belief, Passover is not part of the equation, even though Passover initially played a very big part of the initial calculation of the date. Passover, during the time of Christ, was celebrated on the first full moon after the Vernal Equinox, so this calculation is essentially saying, the first Sunday after this 1st day of Passover. Unfortunately, after the destruction of the temple and the dispersion of the Jews, their date of Passover fluctuated and sometimes occurred before the Equinox. Those Christians who merely followed the Jewish calculations of Passover and inserted Pascha on the following Sunday were condemned for following a wrong calculation.
Just as it is difficult today for those without proper tools and knowledge of the hours of the day, this “simple” calculation was actually difficult for all the Churches to follow, and to amend the wrong calculations the Church came up with a Paschal Cycle. The Orthodox came up with a 19-year cycle and the Catholics came up with an 84-year cycle. This was the first separation of the Paschal dates for the East and West.
The next separation began when the Gregorian calendar became used in the West in 1582. The reason for the new calendar was simple, the observed Spring Equinox (12 hours of day and 12 hours of night) and its marked date on the Calendar was 10 days off. This was caused by an inaccurate amount of days per year. The Julian calendar (the previous calendar) said that there were 365 days a year and added a leap day per four years (365.25 days/year). Unfortunately this was not terribly accurate, which caused the date to move after hundreds and thousands of years. When first established in 45 BC, Julius Caesar marked March 25 as the Vernal Equinox, by the year 300 AD it was observed on March 21st and by 1500 AD it had moved to March 11th. The Gregorian Calendar makes this addition, every 400 years 3 leap days will be skipped on the years that end in ’00 unless that year is divisible by 400. Hence, 1900 was not a leap year, but 2000 was. These 3 omitted day’s lowers the yearly average to 365.2425 days/year. When it was started, the Gregorian calendar jumped from March 11th to March 21st to make up for the 10-day difference over the 1200 years from the 1st Ecumenical Council.
In 1923, Greece officially accepted the Gregorian calendar (“New Calendar”), which jumped from Wednesday being February 15th to Thursday being March 1st. In May 1923, the Ecumenical Patriarch (Constantinople) Meletios IV called an “Inter-Orthodox Congress” to discuss the calendar issue. Though not at once, 8 Churches did move to the Gregorian calendar (Constantinople, Alexandria, Antioch, Greece, Cyprus, Romania, Poland and eventually Bulgaria in 1968). The Churches of Jerusalem, Russia and Serbia, along with the monasteries on Mount Athos, continue to use the Julian calendar. Though the Gregorian calendar prevailed in Greece and in the Churches of Constantinople and Greece, Pascha is still celebrated according to the Gregorian Calendar, for all Orthodox Christians to celebrate this, the Feast of Feasts, on the same day. This reason is why we see Orthodox Christians celebrating Christmas on two separate days, December 25th and January 7th. In reality, we are both celebrating on December 25th; it just depends on which calendar you use and how that relates to the prevailing Gregorian calendar of modern times.
This post was written by Andrew Athanasiou