A reader writes:
I know that Passover and Good Friday normally occur within days of each other. If I am correct, it is believed that the Last Supper was a Passover Seder with Christ being tried and crucified the following day.
I am aware that Good Friday is always celebrated on a Friday whereas Passover can be any day of the week.
What I don't understand is why this year they are a month apart.
And another reader speculates:
I thought that the Easter celebration was supposed to fall somewhere in closer relation to the Passover celebration. Does this have something to do with leap year?
The Last Supper was indeed the Passover; thus Holy Thursday, in the year that Christ was crucified, fell on Passover. That made Easter, the day that Christ rose from the dead, the Sunday after Passover.
Because Christians in different areas were celebrating Easter on different days, the Council of Nicaea, in A.D. 325, established a formula for calculating the date of Easter. That formula was designed to place Easter at the same point in the astronomical cycle every year; if followed, it would always place Easter on a Sunday after Passover. And indeed, that formula is still followed today.
The answer, as William H. Jefferys, the Harlan J. Smith Centennial Professor of Astronomy (Emeritus) at the University of Texas at Austin, explains, is that, since the standardization of the Hebrew calendar in the fourth century A.D., "actual observations of celestial events no longer played a part in the determination of the date of Passover." Thus, "the rule for Passover, which was originally intended to track the vernal equinox, has gotten a few days off."
The same thing has happened with the Eastern Orthodox calculation of the date of Easter. Because the Eastern Orthodox still use the astronomically incorrect Julian calendar, rather than the Gregorian calendar that was adopted in the West in 1582, the Orthodox will celebrate Easter this year on April 27.
With the adoption of the Gregorian calendar, the West brought the calculation of Easter back into sync with the astronomical calendar. In other words, the Western date of Easter is the most closely aligned to the astronomical cycles on which the date of Passover is supposed to be based.
For more information, check out "How Is the Date of Easter Calculated?"
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