cc433336@longs.lance.colostate.edu (Constantinos A. Caroutas) (02/03/91)
As you know, Christ was crucified in the week of the Jewish Passover
and resurrected on the Saturday of the Jewish Passover. At the
Ecumenical Synod of 325 in Nice, Asia Minor, the bishops decided
when to celEbrate Easter. Having in mind the events, they decided to
celebrate on the Sunday after the Saturday on which the Jewish
Passover occurs. That is, right after the Passover.
But, when is the Saturday of the Jewish Passover? The Jews use a
lunar calendar for their religious purposes. There is, however,
an equivalent for this case in the Julian calendar. The Saturday
of the Jewish Passover is the first on or after the first full
moon after 20 March (of the Julian Calendar).
Please note that the Julian calendar is currently 13 days behind
the Gregorian calendar (which we currently use). That is, 1 February
1991 GC = 19 January 1991 JC. According to the Julian calendar,
every year that is divisible by 4 is leap. According to the Gregorian
calendar, every year divisible by 4 is leap unless it is divisible
by 100; in that case, it has to be divisible by 400 to be leap.
Anyway, the bishops at the Synod of 325 agreed on a calculation
to determine the date of the full moon in question. Then the
Easter Sunday would be the first one after that full moon. I
present the calculation below:
1. Take the year, divide it by 19 and take the remainder. If the
remainder is 0 make it 19.
2. Take the remainder found above, multiply it by 19, add 15, and
then divide by 30 and take the remainder.
3. Add that remainder found in step 2 to 21 March. That is the
date of the full moon in interest. The first Sunday after it
is the Easter Sunday.
The above is for the Julian calendar. Add the difference between
it and the Gregorian calendar (currently 13 days) to 21 March to
convert to Gregorian calendar.
While the calculation above is quite accurate, it is not exact.
After 16 centuries it overshoots the full moon date by 4-5 days.
So usually, Easter Sunday is not one day after the Saturday of
the Jewish Passover, but eight.
The calculation going off (about 1 day every 400 years) is not the
only problem. Earth takes 365 days 5 hours and almost 49 minutes
to go once around the sun. The 5:49 hours add up to almost 97
days in 400 years. So, with the Julian calendar having 100 leap
years every 400 years, it meant that the seasons were shifting.
A pope by the name Gregory whose hobby was astronomy found that
and proposed a new calendar to fix that. The Orthodox, of course,
did not accept it. It is as I have decribed above. Plus, since
it is not exact, astronomers will have to make adjustments
[a day added or subtracted (I'm not sure)] every several thousand
years.
Pope Gregory also realized that the Jewish Passover was moving
toward the summer. It was not a feast of the spring. Adding to
the shift in the calculation for the Easter, it meant that the
Easter was moving toward the summer at the average rate of 1
day every century. And, once at summer, it would not stay there.
It would keep moving forward.
Switching to the new calendar meant that something had to be
done to keep Easter in spring. So, pope Gregory decided to
have Easter on the first Sunday after the first full moon
after 20 March. Since he did not have the authority to make
that change, the Orthodox church did not accept it. Only the
Ecumenical Synod has the authority to make that change. So,
the Orthodox Easter is found on the Julian calendar and then
that date is converted to the Gregorian calendar.
Considering the above, the Orthodox Easter currently occurs
on the same date as the Western, or 4 weeks later, or 1 week
later, or 5 weeks later. When the difference is 0 or 4 weeks,
then the Orthodox Easter Sunday is right after the Saturday
of the Jewish Passover.
I hope it all makes sense now.
Leap seconds. The Earth is slowing down and thus the average
solar day is a bit more than 24:00:00 hours now. Every few
years, the difference adds up to 1 second which is added at
the last moment of a year.
Orthodox using Julian or Gregorian calendar: In countries
where an Orthodox church has a "good relationship" with the
state the church uses the Gregorian calendar. Otherwise, it
uses the Julian calendar. For example, the Russian Orthodox
church uses the Julian calendar, while the Orthodox church of
America --established by the Russian Orthodox church-- uses
the Gregorian calendar.
The Ecumenical Synod has the right to change the church
calendar, but we cannot have one until the churches unite.
Since the Gregorian calendar has the same objective as the
Julian calendar -the Gregorian calendar is simply more
accurate-- it is certain that an Ecumenical Synod would
approve it. So, some churches adopted it for the sake of
convenience. It is quite disappointing that some stick to
the Julian calendar. I believe that if the curches unite,
they'll all adopt pope Gregory's way to determine the
Easter date. And, that is certainly the least of the
differences between the churches.
--
Constantinos A. Caroutas
_______________________________________________________________________________
"People tell me I can't have everything | from "On The Way Up"
But still I want to have it all | Elisa Fiorillo I'm on the way up; look out" | I AM (1990) _______________________________________________________________________________mls@sfsup.att.com (Mike Siemon) (02/06/91)
I think there are some historical misunderstandings in Constantinos Caroutas' note on determining the date of Easter: > at the Ecumenical Synod of 325 in Nice[a], Asia Minor, the bishops decided > ... to celebrate on the Sunday after the Saturday on which the Jewish > Passover occurs. This the common *modern* Orthoox statement of the Nicene rule; the common *modern* Western statement (Catholic and Protestant) is "the first Sunday after the full moon following the vernal equinox." Since much of what Constantinos says later hinges on these differences in phrasing, including matters of import for the schism of East and West, I think it worth taking a look at this. Frankly, it is NOT KNOWN what the Nicene statement was, as we do not have a record for Nicea such as exists for many other councils (regional or ecumenical.) The *issue* about Easter at Nicea was controversy between the Asian (i.e. Anatolian) practice of dating the annual Passion-and- Resurrection observance by the Jewish calendar (so that Christian pascha was dated by Jewish pesach starting on the 14th day of the Jewish month of Nisan) and the Roman practice of celebrating the Resurrection on the Sunday closest to March 25th (understood by the Romans to have been "the" date of Easter in their non-lunar calendar.) This controversy arose in the second century; Irenaeus remarks on it around 200 A.D. -- and it got worse over the next century. Essentially, the Romans felt that Asian practice was "heretical" in that it seemed to them that Christians were being re- quired to "observe" Jewish moons (contra Paul's "command" in Colossians.) I think the Roman objection was, in this case, fatuous; but you will see how it influences the Western statement of the Nicene decision. The Orthodox statement still seems to retain a trace of Quartodeciman heresy! :-) Pinning things to the vernal equinox (then about March 21st) was a way to pick up the major intent of the Eastern dating along with an agreement that the central feast was Resurrection Sunday. To this extent, making Pascha a Sunday "anniversary" of the Resurrection tied roughly to the equinox, the Nicene compromise worked pretty well, and Quartodecimans ceased being any "problem." Incidentally, my "tied roughly to the equinox" covers both the Western and the Eastern statements, as the Jewish calendar indeed ties Pesach roughly (i.e., over a lunar cycle) to the equinox. The Western mention of a full-moon after the equinox is a way of "saying the same thing" as in the Jewish calculation -- 14 days after the nominally-equinoctial moon of Nisan. The main difference (for the current purposes) between Jewish and Christian calculations here is that in the West the solar year is basic (the equinox date) and adjustments to the moon secondary (the full moon *after* the equinox) whereas in the Jewish calendar the lunar period is basic (so that Nisan is simply the sixth-month after a Tishri New Year, and it "tracks" the equinox because intercalary months are added to compensate for a lunar 12-month having only 354 days and so falling "short" of a solar years.) > Anyway, the bishops at the Synod of 325 agreed on a calculation > to determine the date of the full moon in question. Then the This is incorrect, as subsequent history adequately demonstrates. The bishops at Nicea made a "high level design decision" but did NOT provide a method of calculation (an "algorithm" or an "implementation" of their design -- think of Nicea as operating like a standards body :-)) For a century or two after Nicea, MOST Christian churches took their date for Easter from encyclical letters prepared by the patriarch of Alexandria. These indeed will have followed some basic luni-solar calendar (either the Babylonia one == Jewish calendar or more likely the Greek calendar in use at Alexandria; all of these use the conventional "Metonic" cycle of 18 or 19 years.) Breakdowns in communications -- and mutual suspicions among the partriarchates in consequence of ongoing Christological disputes, so that there was an unwillingess to "depend" on Alexandria in this matter -- eventually led the West to concoct a series of "tables" to be used for the calculation. I am unfamiliar with further developments in the East, and it is quite possible that the "rule" Constantinos gives (with its specific reference to the Passover Sabbath) may date from this same period. In the West, an early and rather poor table got embedded in the practice of the Irish Church while it maintained only minimal contact with (and did not grant authority to) Rome. Meanwhile, Rome had adopted a table that is more or less an instantiation of the calculation rule Constantinos set out in his modulo 19 stuff. [ The dispute at Whitby between the Irish and Roman monks largely hinged on the Roman tables being demonstrably "better" at implementing the Nicene "rule" than the tables used by the Irish. Calendar studies to prove this point became important in English monateries, and the Venerable Bede has a (quite good, for its day) discussion of the relevant astronomy and calendar handling. My comments about the history derive, in part, from an excellent modern edition of Bede's calendar writings; the introduction is an extensive essay on the history of Easter dating in the early church and gathers most of the relevant patristic citations. -- mls ] > Pope Gregory also realized that the Jewish Passover was moving > toward the summer This is nonsense. The slippage had NOTHING to do with Jewish Passover dating, which is moderately well tuned to the seasons by its complex cycle of inter- calary months (a 13th month every few years.) The calculations Constantinos has just described were BASED on the Julian calendar, which Jews do not use for dating Pesach. Confusions like this lead me to believe that whatever ordinary Orthodox believers think, the linkage of their Easter dating to a Passover Saturday, is indirect or nonexsistent (in other words, they *do* observe the "correct" Nicene canon :-)) I'm not trying to be nasty here; just observing that unless you get the details *exactly* right, you are in some danger of getting very badly misled. The slippage was PURELY that of the Julian calendar against the seasons, with its overlong approximation of a year as 365.25 days; this, you have already refered to in connection with the leap-year rule. [Incidentally, there is no ground to believe that Pope Gregory had any interest -- amateur or not -- in astronomy; like the Alexandrian patriarchs before him, he referred the question to professional staff -- the "Gregorian calendar" and all its very complex Easter calculations were the work, primarily, of Clavius.] I won't get into a discussion of Gregorian Easter dating algorithms; I don't think this group could tolerate discussions of _epact_ :-) Those who are inter- ested can look up calendar articles in 11th edition Encyclopedia Brittanica or hunt through indexes to Scientific American; there was a nice article on this around the centenary of the adoption of the Gregorian calendar, in 1982. > Switching to the new calendar meant that something had to be > done to keep Easter in spring. This really states it backwards. The whole POINT of the new calendar was to keep Easter tied "properly" to the vernal equinox. The "tables" and "rules" used -- and something more or less has to be so used, or we must rely on dissemination of accurate astronomical data, as used to be done when the Alexandrian encyclicals prevailed -- were proving to be contrary (and for totally irrelevant astronomical reasons) to what was understood as the intent of Nicea. > Since he did not have the authority to make > that change, the Orthodox church did not accept it. I think you have seriously misunderstood the case. If the Eastern bishops feel (as you seem to, and as I think is demonstrably false on historical grounds, but let that pass) that some specific algorithm was agreed on at Nicea, then it is clear that they have reason to deny papal authority to *change* that rule by "monarchical" proclamation. But let me point out that most Protestants -- after some centuries of hesitation just because THEY do not grant any such papal authority, either -- go along with the Gregorian change. I don't think that a serious look at Nicea would stand in the way of Orthodoxy doing the same thing -- though of course I do not regard that as any strong argument that you "should" do so. In any case, Constantinos' note is sufficiently confused about matters like Passover and the context of the Gregorian change, that I would recommend he (or other Orthodox readers) find someone sufficiently well-informed in BOTH astronomy/calendar-studies AND patristic history, to clarify the issue for him. I would greatly appreciate having someone better informed post ACCURATE statements of how (various) Orthodox churches calculate the date of Easter. I don't want to make a big deal of "disputing" Constantinos, but his mistakes of description about Western practice leave me with no confidence in the accuracy of his statements about Orthodoxy. Very few Westerners know (or care about) the details of calendrical issues; I expect the same is true in Orthodox churches. What I would like is some *authoritative* reference on Orthodox practice here. > The Ecumenical Synod has the right to change the church calendar, but we > cannot have one until the churches unite. Since the Gregorian calendar > has the same objective as the Julian calendar -the Gregorian calendar is > simply more accurate-- it is certain that an Ecumenical Synod would > approve it. So, some churches adopted it for the sake of convenience. It > is quite disappointing that some stick to the Julian calendar. I believe > that if the curches unite, they'll all adopt pope Gregory's way to determine > the Easter date. And, that is certainly the least of the differences between > the churches. Yes; it would seem that we are in basic agreement that this is hardly a big issue :-). What I want to urge is that the "problem" comes in seeing Nicea as having implemented a specific form of calculation. I suggest you want to investigate THAT question historically, and my best guess is that you will find little evidence for such an assumption. If Nicea in fact gave no practical way to make a calculation, then whatever is done in the individual churches is _ad hoc_ and is subject to change as convenient, as long as the ecumenical decision is faithfully obeyed. I would suggest that obedience to Nicea is NOT in question in any of the churches, East or West -- and it is mostly the "symbolic" gesture of the Western Pope single-handedly "changing" the date of Easter that is found offensive in the East -- but that such offense can be foregone if you can look with charity on the context in which the "change" was made. -- Michael L. Siemon "O stand, stand at the window, m.siemon@ATT.COM As the tears scald and start; ...!att!attunix!mls You shall love your crooked neighbor standard disclaimer With your crooked heart."