See the Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac, (my version 1961), pp 420-429. “The rule for determining Easter as commonly expressed in popular language is somewhat misleading because it is not a precise statement of the actual ecclesiastical rules. In order that the date should be incontrovertibly fixed, and determinable indefinitely in advance, tables based on the Metonic cycle were constructed to be used permanently for calculating the age of the Moon. Easter is determined by the “ecclesiastical moon” defined by these adopted tables, which is not strictly identical with the real Moon.” It goes on for 9 pages, with tables and examples. In 1954 the date for Easter differed from the common definition, but only for part of the world. The Metonic cycle is a 19 year cycle. Each year has a “Golden Number” which is used to index into the tables that determine when Easter occurs for that year.
Welcome to the Straight Dope Message Boards, whharr, we’re glad you’ve found us. For future ref, when one starts a thread, it’s helpful to other readers to provide a link to the column in question. Saves search time and helps keep us on the same page. No biggie, you’ll know for next time, and I assume you’re talking about How is the date of Easter determined?
In terms of your statement, I dunno, but I do note that you mention “only part of the world.”
As Easter is not an astronomical phenomenon, but an eccesiastical one, Easter is everywhere at the same time. There are two dates on the Earth at any given time due to the International Date Line, but Easter doesn’t take that into account, apparantly. So in 1954, for parts of the world, Easter did not occur on the date that it would have by the common definition that is stated in the original post in The Straight Dope. For parts of the world, it did. So I guess, technically, Easter was on two different days in 1954.
Your quote from the Nautical Almanac is quite correct. The date on which Latin (western) Easter Sunday falls is determined by a set of mathematical rules based on a purely hypothetical ‘ecclesiastical’ moon. One of the reasons for this methodology is that it gives a date for Easter Sunday which is the same for all locations around the world, regardless of their longitude. The colloquial version of these rules…“the first Sunday after the first full moon falling on, or after, 21 March”…is merely a simplified version which is easy to remember and gives the same answer as the more complex rules in most calendar years. In those years where the colloquial version, based on the actual moon, would lead to different Easter dates (e.g. 1954) the more complex rules based on the hypothetical moon ensure uniformity throughout the world. Easter Sunday was not technically on two different dates in 1954.
More interesting (than how the priests determine when the performance is scheduled), would be an explanation of why the date has to move around at all.
an event that formed the basis for the Christian faith, the Resurrection, took place on a date in, say, AD30. If one were to let the priests decide what date that was, adjusted for changes in the way the calendar is calculated, then we could celebrate the Resurrection on the same date each year. Yes, some will say that the relationship to ‘Passover’ is overriding, mystical, essential…but is it, really?
Perhaps, since the event is so seminal, the priests exerted their power and magical ability to reveal the will of God by presenting the date that Easter would be celebrated to the people. The differential between Eastern Orthodox and Latin dates for Easter is further evidence that setting the date for Easter is a way to reinforce the authority of the priesthood of each sect, to set forth the idea that ‘our Christian belief is the only true faith, all the others are apostates’…
Consider the fun we all would have if we celebrated other events according to the phases of the moon…the effect on birthdays, anniversaries, patriotic holidays, etc. would be far more profound that the current convenience of moving the date of celebration to put it on a Monday, creating a 3, sometimes 4, day weekend.
There are several movable feasts (as they’re called in the Christian faith), and Easter is the best known one.
Why does it move around? Because it was suppose to be on Passover! There’s nothing mysterious with that. There’s no conspiracy. It was suppose to be on Passover because that’s when it happened.
There’s problem is having a religion that was suppose to completely make this second religion completely obsolete, and then having one of your major holidays dependent upon when that other religion celebrated one of their holidays!
Thus, the people who were in charge of the Church decided they’d figure out their own way of figuring out when Easter fell with out depending when the Jews decided it was Passover. Since the month of Nissan (the Hebrew month when Passover falls) is a spring month, it should always fall around the Spring Equinox. Since Hebrew months start with the new moon, and since the first day of Passover is on the fifteenth of Nissan (during the full moon), the church’s official definition of Easter was the first Sunday after the first full moon after the first new moon after the Spring Equinox (or something like that).
The problem with that definition is that it doesn’t tell you when Easter will fall and makes planning somewhat difficult. You know it’ll fall sometime around this date, but when? However, if you know the days in a lunar year vs. the days in the solar year, and more or less when the Jews would add a leap month to their calendar, you could calculate when Easter would more or less fall during any year. Now, you could make plans!
Other religions (especially those with lunar calendars) have done similar things. If I want to fly somewhere on the Fifteenth of Moomba, it’s sort of hard to make plans when I don’t know when Moomba starts. Thus, most religions that depend upon a lunar calendar have calculated and fixed their dates.
The whole point of basing Easter on the moon and such was to ensure that it would be on the same date every year. But it’s the “same date” based on a different calendar than the one we use. Jewish feasts are always on the same date each year, according to the Jewish calendar, while meanwhile, Independence Day, say, falls on a different date each year in the Jewish calendar.
doh, that makes too much sense.