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== Notes to Excel formulas ==
Both formulas on article page work correct only from 1900 to 2203 in the 1900 date system and provide only the Gregorian Easter Sunday dates
<h3>Calculate Gregorian Easter date</h3>
The actual state is a reduction to <100 characters with full functionality from 1900 to 9999
<table border=0 cellpadding=0 cellspacing=0 style='margin-left:10px;'>
<tr><td><b>date&#160;system</b></td><td align=center><b>Excel formula</b></td></tr>
<tr><td valign='top'><br>1900</td><td nowrap><FONT face='Arial Narrow' >
=FLOOR((5&-A2)+97%*MOD(18.998*MOD(A2+8/9,19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9),30),7)-34
<br>or longer<br>
=FLOOR((4&-A2)-5+97%*MOD(18,998*MOD(A2+8/9;19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9);30);7)+1
</FONT></td></tr>
<tr><td>1904</td><td nowrap><FONT face='Arial Narrow' >
=FLOOR((4&-A2)-6+97%*MOD(18,998*MOD(A2+8/9;19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9);30);7)+2
</FONT></td></tr>
<tr><td>190x</td><td nowrap><FONT face='Arial Narrow' >
=FLOOR((4&-A2)-DAY(5)+97%*MOD(18,998*MOD(A2+8/9;19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9);30);7)+DAY(1)
</FONT></td></tr>
</table>
Excel community: http://www.online-excel.de/fom/fo_read.php?f=1&h=58861&bzh=72926&ao=1#a123x <br>
<br>The Gregorian Easter period began 1583 and not 1900 - and that's why it must be enhanced (1900 date system).
<table border style='margin-left:10px;'><tr><td nowrap><FONT face='Arial Narrow' >
=<font color=red><b>A2&TEXT(</b></font>FLOOR((5&-A2<font color=red><b>-(A2%<19)/5%%</b></font>)+97%*MOD(18.998*MOD(A2+8/9,19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9),30),7)-34<font color=red><b>,"-MM-DD")</b></font>
</FONT></td></tr></table>
:: <b>Notice:</b> This formula provides the same results like Gauss from 0001-9999, you could enhance it again with starting <font color=red><b>=TEXT(A2,"0000")&...</b></font> <br> 17:42, 23 June 2013 (UTC)
<h3>Calculate Julian Easter date</h3>
As date: The following works from years 1900 to 9999 (1900 date system)
<table border style='margin-left:10px;'><tr><td nowrap><FONT face='Arial Narrow' >
=(A2&TEXT(FLOOR((5&-1908-MOD(A2,28))+MOD(19*MOD(A2,19)-14,30),7),"-M-D"))-35
</FONT></td></tr></table>As text: The following works from years 0001 to 9999 (1900 date system)<br>
<table border style='margin-left:10px;'><tr><td nowrap><FONT face='Arial Narrow' >
=TEXT(A2,"0000")&TEXT(FLOOR((4&-1908-MOD(A2,28))+MOD(19*MOD(A2,19)-15,30)-4,7),"-MM-DD")
</FONT></td></tr></table>
<h3>Combination of Julian/Gregorian Easter date</h3>
As <b>YYYY-MM-DD</b> text: The following works from years 0001 to 9999 and any breakpoint from 1 to 9999 (here it is <font color=red><b>1583</b></font>), taking 1900 date system<br>
<table border style='margin-left:10px;'><tr><td nowrap><FONT face='Arial Narrow' >
=TEXT(A2,"0000")&TEXT(IF(A2&lt;<font color=red><b>1583</b></font>,FLOOR((4&-1908-MOD(A2,28))+MOD(19*MOD(A2,19)-15,30)-4,7),FLOOR((5&-A2-(A2%<19)/5%%)+97%*MOD(18.998*MOD(A2+8/9,19)+INT(68%*INT(A2%)-INT(A2%/4)-5/9),30),7)-34),"-MM-DD")
</FONT></td></tr></table>Frank Schneider, 08:55, 5 November 2013 (UTC)--
<br>
::First two Excel formulas of main page have a lot of restrictions - is it possible to replace them? 22:10, 30 September 2013 (UTC) <span style="font-size: smaller;" class="autosigned">— Preceding ] comment added by ] (]) </span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->
<br>
:::: I added the universal formula. Frank Schneider, 08:55, 5 November 2013 (UTC)--

== Addition to table, claiming regular pattern ==

Is the table addition in by ] comprehensible and sufficiently connected to the remainder of the article that readers will understand why it is included? Is this table useful to readers, and therefore merit inclusion? Is "regular pattern" a correct and useful titile for that portion of the table? ] (]) 19:54, 3 March 2013 (UTC)
*'''Simplify or explain'''. The table is confusing, but if additional explanation were offered it would make more sense. Alternatively, the article could include a simplified walkthrough of what all of those dates mean for a single year. <span style="color:orange">]<sup>]</sup></span> 19:21, 5 March 2013 (UTC)
*:This makes sense. Perhaps split into two tables preceded by explanations? Comparisons should still be easy enough for reader, if tables are in proximity to each other.  — ] ]&nbsp;] 20:35, 14 March 2013 (UTC)

== Mental arithmetic ==
>> step1 needs to be bracketed to clarify it is the +29 that is conditi0onal on y mod 19 = 5 or 16.
>> and some clarification is also needed on what mod 30 really means here, since mathematically it should be in the range 0-29 or (sometimes) -14..15 but in the samples 55 mod 30 = 25 but 88 mod 30 = -2.
] (]) 14:01, 19 May 2013 (UTC)
:Step one: using 45 - (y mod 19 × 11) mod 30 + 29, if y mod 19 = 5 or 16, to determine the date of PFM (PFMd).
:Step two: using (y mod 100 + + c + PFMd) mod 7 to determine the day of PFM (dPFM).
:Step three: using PFMd + 7 - dPFM to determine the date of Easter (if the result > 31 the month = April).
where c = 3 for years 1900 ~ 1999, c = 2 for years 2000 ~ 2099, and c = 0 for years 2100 ~ 2199.

Take a few examples:
*The year 2000 mod 19 = 2000 - 1995 = 2000 - 2000 + 5 = 5 hence 5 × 11 mod 30 = 55 - 30 = 25, so PFMd = 45 - 25 + 29 = 49 (Apri 18), and 2000 mod 100 = 0 hence dPFM = (0 + 0 + 2 + 49) mod 7 = 0 + 0 + 2 + 0 = 2 (Tuesday), so Easter Sunday = 49 - 31 + 7 - 2 = 18 + 5 = 23 April.
*The year 1992 mod 19 = 16 hence 16 × 11 mod = 26, so PFMd = 45 - 26 + 29 = 48 (April 17), and 1992 mod 100 = 92 hence dPFM = (92(8) + + 3 + 48) mod 7 = 1 + 2 + 3 + 6 - 7 = 5 (Friday), so Easter Sunday = 48 - 31 + 7 - 5 = 17 + 2 = 19 April.
*The year 2117 mod 19 = 2100 - 2090 + 17 - 19 = 2100 - 2100 + 10 - 2 = 8 hence (8 × 11) mod 30 = 88 - 90 = -2, so PFMd = 45 - (-2) = 47 (April 16), and 2117 mod 100 = 17 hence dPFM = (17 + + 0 + 47) mod 7 = 3 + 4 + 5 - 7 = 5 (Friday), so Easter Sunday = 47 - 31 + 7 - 5 = 16 + 2 = 18 April.
So it is very easy to determine the date of Easter! --] (]) 10:06, 8 March 2013 (UTC)
::Hello !!! Try it the other way around. I'll give you the dates: '''22 March''' and '''25 April''', and you determine the year (the last and the next occurrence). Thanks. ''':'''–D ] (]) 16:07, 23 March 2014 (UTC)

== Still confused ==

I am still confused as to why the golden number (date of the full moon) can be only 19 different days when a month is 30 or 31 or 28 (or more appropriately a lunar month is 29 or 30 days). Are there some days in the range of Mar 21 - April 20 or whatever that cannot be a full moon?
(The golden number of any Julian or Gregorian calendar year can be calculated by dividing the year by 19, taking the remainder, and adding 1). This leaves only 19 possible days for a full moon out of 29 or 30.

:The golden number is note a date; I don't have time to explain right now. ] (]) 19:09, 17 April 2014 (UTC)

:: In the Julian computus, there are only 19 dates in each 29-or-30-day cycle that the full moon can occur on. By the time of the Gregorian reform, those dates were about 4 days in error compared to the actual moon. In the Gregorian computus, in any given century there are only 19 dates possible for a full moon, but at the start of some centuries those dates shift ahead or back by one day because of the "solar correction" and "lunar correction" components of the formula for the epact. ] (]) 19:13, 19 April 2014 (UTC)

:::I don't know ''all'' the details of the computus, but I do know this much. First, don't confuse the actual astronomical events with the calendar. Predictive calculation of astronomical events was not possible when computus was first created, nor even when the Gregorian reforms occurred. One could only tell when these events occurred through observation of the occurrence, at or after the fact. But the church needed to predict the Paschal moon in order to tell when Pascha was supposed to be celebrated, and only after that date was set could it know when to begin preparations for Pascha, the season that developed into Great Lent. They needed not only to be predictive, but up to two months in advance! The church was practical. It used the calendar as the best means then known to look ahead. Then it set up the computations based on the calendar. And in earliest times, that was the Julian calendar in the west, and the Alexandrian in the east (at least for the easterners who weren't depending on the Jews to make determinations of when Passover occurred, on the basis of the Hebrew calendar. (See the issue about that which was considered at the ].)

:::Ancient observations of what ''had'' occurred historically were much more sophisticated than is normally supposed today, and records had been kept over centuries of time. Alexandria's famous library was a primary repository for much of such ancient knowledge, and that is why Julius Caesar went there to consult the best astronomers in constructing the Julian calendar in the first place, and why that calendar was a practical breakthrough in calendar quality. (The Alexandrian one was no slouch either.) But the ancients knew that it took 19 years for the moon to run through a whole number of lunar cycles within a whole number of years, and that is what the 19 is about in the computus. Computus also has to consider what days of the week the Paschal moon falls on, since Pascha must come on a Sunday following that moon (not on that moon). The reason in the Gregorian computus that there are only 19 dates possible in a given century (if that's really true), would have to do with the fact that in the Gregorian calendar, only one century year out of four is a leap year (unlike the Julian calendar). The computus accounts for leap years, because it is based on the calendar, and you have to account for that in order to keep the days of the week right.

:::Both calendars, over a sufficient number of centuries, and the Julian calendar more so, contain "inaccuracies" compared to actual astronomical events. They accumulate those inaccuracies over time, and eventually the discrepancies add up to a certain number of days. Within the last 50 years we have become able to calculate astronomical events, both observationally and predictively, with such accuracy that we can notice fractions of seconds (today, even microseconds or less) of differences. And we know that unpredictable astronomical events can and regularly do introduce tiny fluctuations in all these measures. We even adjust for those on a fairly regular basis now - perhaps you've heard of the "leap second". Suffice it to say that no calendar will ever be able to make predictions with complete accuracy if you project it far enough into the future. Computus survives because, in principle, it is still practical. Hope this helps some. ] (]) 20:01, 19 April 2014 (UTC)

Also, this year in Illinois the Vernal Equinox was Mar 20th. The equinox happens at a certain instant and in Illinois it was on Mar 20 but in Tokyo it was already Mar 21 since they are like 12 hours ahead of Illinois. What time zone do they use for equinox?

: The meridian of Jerusalem by default; there was no knowledge of the problem (of longitude) when this algorithm was devised. ] (]) 19:09, 17 April 2014 (UTC)

:: Since the authors of the Gregorian calendar were working in Italian cities, I expect their tables were calibrated to the observations of local Italian astronomers. ] (]) 19:13, 19 April 2014 (UTC)

One last question. Is Passover always in the middle (14th) of a month (often coinciding with Easter but occasionally almost a month ahead due to the extra month added sometimes to the year)? So is Passover always on a full moon? <span style="font-size: smaller;" class="autosigned">— Preceding ] comment added by ] (]) 17:58, 17 April 2014 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->

: The month (Nisan, IIRC), and all other months on the Jewish calendar, start at a new moon, so the 14th of the month is, therefore, a full moon, ] (]) 19:09, 17 April 2014 (UTC)

== Drift in ecclesiastical full moon ==

It would be more helpful to tweak the wording, rather than nuke the section entirely. The value of delta T over 2,000 years has reached about 3 1/2 hours. The shift in the time of full moon over the same period is much the same. So the one cancels the other out. ] (]) 10:44, 14 May 2015 (UTC)

: The deleted section appears to be largely based on "original research" which doesn't belong here. ] (]) 10:50, 14 May 2015 (UTC)

::(ec)My mistake. I see the objection is not to this bit, it's to the bit above. Nobody claimed it was badly written when it was part of a stable version five years ago. ] (]) 10:54, 14 May 2015 (UTC)

::You said it was badly written. Now you claim it's original research. You seem to be making this up as you go along. The fact is that the change in delta t and the secular acceleration of the moon has been known for years. ] (]) 10:58, 14 May 2015 (UTC)

::: Actually it is both (original research as there is no reference and it is badly written - the cited numbers 84 and 19 come from nowhere). The fact that it was there five years ago is not relevant - it was evidently removed for the reasons which I mentioned just now. Changes in Delta T and the secular acceleration of the moon are indeed well known but you do not provide references for your claim. ] (]) 11:03, 14 May 2015 (UTC)

::::It was removed as part of a batch by an editor claiming the article had been edited by a sockpuppet. The content was never questioned. ] (]) 11:45, 14 May 2015 (UTC)

:::::Then why is it unsourced and badly written (see my earlier comments). Such content does not belong in WP. ] (]) 11:54, 14 May 2015 (UTC)

::::::I don't see it's badly written. Lichtenberg theorised a mixture of 200 and 300 - year correction steps. The actual error to be compensated is one day in about 210 years, so there will be many more 200 than 300 - year steps. The actual ratio turns out to be 84 to 19, but that's a side issue that doesn't affect the structure of his scheme. ] (]) 12:09, 14 May 2015 (UTC)

:::::::If the section which I deleted comes from Lichtenberg's paper this should be indicated more clearly. Still I do not feel that this level of detail belongs here, perhaps it should be moved to ]. ] (]) 12:26, 14 May 2015 (UTC)

::::::::The consensus is that this level of detail does belong here. ] (]) 13:45, 14 May 2015 (UTC)

:::::::::Kindly provide some proof of your claim. ] (]) 13:58, 14 May 2015 (UTC)

::::::::::It was a stable version five years ago. ] (]) 15:21, 14 May 2015 (UTC)

:::::::::::That is a very long time ago. So apparently nobody objected to its deletion five years ago? You still have not given any evidence that the deleted section is from Lichtenberg's paper. ] (]) 15:42, 14 May 2015 (UTC)

::::::::::::Obviously it's not word - for - word because that would be plagiarism. As for your other point, doubtless many editors objected to the loss of their work when Jc3s5h arbitrarily turned the clock back. ] (]) 15:55, 14 May 2015 (UTC)

{{od}}Lichtenberg describes the replacement of solar equations (common centennial years) and lunar equations (drift of one tithi in 312 1/2 years) with a unified correction cycle which provides the same number of epact corrections over the cycle. <small class="autosigned">—&nbsp;Preceding ] comment added by ] (]) 16:20, 22 May 2015 (UTC)</small><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->

:You must be referring to another paper by Lichtenberg or someone else. I have read the Lichtenberg (2003) paper twice and I don't see anything which matches your claim. ] (]) 10:44, 23 May 2015 (UTC)


==Whether the pattern repeats==
::He most certainly does use unified corrections (200 and 300 year steps). How do you claim he makes the adjustments? ] (]) 12:49, 23 May 2015 (UTC)
<!-- ] 10:02, 21 September 2123 (UTC) -->{{User:ClueBot III/DoNotArchiveUntil|4850964145}}
{{Ping|Tom Peters}} Tom, what do you think? I added the following paragraph:


One may wonder whether the pattern of dates of Easter repeats. As can be verified in a table of the dates, the dates from 1948 to 2047 are the same as for those 152 years later (2100 to 2199). This period of 152 years is one day short of two ]s, and is a whole number of weeks. Also the dates for 1800 to 1899 are the same as those for 152 years later (1952 to 2051) in all but 11 cases. The epacts differ by 1, as do the dates of the ecclesiastical 14th of Nisan, but usually the next Sunday falls on the same date. It is possible to have the same dates for the 14th of Nisan and on the same day of the week for other intervals, but since the golden number is not the same, this situation lasts for less than 19 years at a time. For example, the 100-year period 1980-2079 is almost repeated 220 years later (2200-2299), but with six cases that don't agree. An interval of 18,000 years achieves this in some cases
::: Lichtenberg's (2003) paper indeed discusses the lunar and solar corrections which are necessary to compute the correct lunar age but the section which I blanked is not a part of his paper as you claim. If you think that the blanked section (which I repeat here)


Footnote (which I can't seem to put here in the talk page): It is easy to verify that this occurs if the interval contains 58 lunar corrections and the golden number of the first of the two years in question is less than 13, or if there are 57 lunar corrections and the first golden number is greater than 12. In either case, these cancel out the 135 solar corrections.
::::''Using a more accurate leap year rule (218 leap years in 900 years with AD 2500 a leap year) the present system has a "lunar jitter" of 2.60 days. The unified correction cycle repeats every 22500 years starting in 1 BC. In this period there are 175 Gregorian solar corrections and 72 lunar ones for a net correction of 103 days. There are nineteen 300 - year correction periods interspersed among eighty - four 200 - year ones. These numbers are unforgettable - 84 is the number of years in the British epact cycle before the Synod of Whitby and 19 is the number afterwards. The 300 - year periods end in 1100, 2400, 3500, 4800, 5900, 7000, 8300, 9400, 10700, 11800, 13100, 14200, 15500, 16600, 17700, 19000, 20100, 21400 and 22500. In the first three millennia of the Christian era the lunar jitter is 3.16 days, which cannot be reduced by moving corrections which would otherwise occur in leap years. The cycle is furthest behind the moon in the 11th century and furthest ahead in the 22nd century.''


and is also a whole number of 400-year Gregorian cycles, but again the golden number will be different, so the pattern does not repeat exactly.
:::::is a part of his paper, please indicate where. ] (]) 13:57, 23 May 2015 (UTC)


Five minutes later Jc3s5h reverted it, saying that it's a "wall of text" that doesn't answer the question I asked at the beginning -- whether the pattern repeats, and he says it repeats in 5.7 million years. Well of course, we all know that. But does that justify reverting my edit? The question I mean is whether the pattern repeats for a while, like a century, and the answer is yes. I think it's quite interesting, and should be in the article. ] (]) 19:25, 10 September 2023 (UTC)
::::::That's not what I asked you. My question was, does he or does he not make use of unified corrections in spaced out 200 - and 300 - year intervals to replicate the 43 epact corrections in 10 000 years? ] (]) 14:16, 23 May 2015 (UTC)


:I was going to revert it and Jc3s5h beat me to it by minutes. It reads ''far too much'' like a blog post, beginning with "One may wonder whether the pattern of dates of Easter repeats" which is exceedingly unecyclopedic. It was also too far too long for the thoughts expressed. Arguably it works better as a talk page post here to open a discussion on whether/how to express your thoughts. ] (]) 19:33, 10 September 2023 (UTC)
:::::::: You're sidestepping the issue. The issue is the section which I blanked because it is unsourced and you keep on trying to put back. Up to now you have not be able to provide a verifiable source. ] (]) 14:26, 23 May 2015 (UTC)


::So why don't you modify the wording instead of deleting the whole thing?? I wish you people would stop complaining every time someone puts something interesting into an article. Nobody is forcing you to read it, after all! Other people might want to read it. ] (]) 20:34, 10 September 2023 (UTC)
:::::::::It's ''you'' who is "sidestepping the issue". I happen to know that's ''exactly'' how he did it. ] (]) 14:43, 23 May 2015 (UTC)
:::I didn't delete it. But if I had I would reject your point because it's not my job to correct your failings. Why should I put effort into dragging out some sort of value in your edit when I can't see any? It's not interesting and it shouldn't be in the article. ] (]) 20:37, 10 September 2023 (UTC)


:::: You and Jc3s5h act like Caesar watching the gladiators, and giving a thumbs up or thumbs down. Who made you the judges? I think it's very interesting that the pattern repeats exactly or almost exactly over periods of 100 years, at certain intervals. Another case I didn't put is that 1700-1747 is exactly the same as 1852-1899. One would think that people interested in Easter would show a bit of Christian charity. ] (]) 09:01, 11 September 2023 (UTC)
::::::::::Provide a verifiable source then. ] (]) 14:58, 23 May 2015 (UTC)
:::::In that case, we may as well have a ]. I'd have reverted it too, per ]. It is a mathematical artefact of no significance. A form of ]. --] (]) 09:22, 11 September 2023 (UTC) revised 09:27, 11 September 2023 (UTC)
::::::<small>I love a thread where pareidolia is an issue. :) ] (]) 10:00, 11 September 2023 (UTC)</small>
:::::::I think the issue is interesting enough that '''''if''''' a good source (other than the dates themselves) can be found, and '''''if''''' it can be stated briefly and clearly, it '''''may''''' be relevant for the article -- but it is up to ] or others who want to include it to demonstrate that. In the Gregorian calendar there is a period-4 stemming from leap years and a period-7 stemming from days of the week, combining into a period-28 (not related to churches, Easter or holidays) so that e.g. from 1901 to 2099, the calendar for any two years separated by a multiple of 28 years is the same (all Mondays fall on the same dates, etc.) - but the "missing" leap years in 1700, 1800, 1900, 2100, 2200 ect. spoil the fun. Incidentally, the true period-400 in the leap years coincide with a whole number of weeks (400*365 + 100 - 3 = 146097 days = 20871 weeks), so there is a true, perpetual period-400 in the Gregorian calendar. -- Is that relevant here? No, but if similar neat patterns could be descirbed for dates of Easter - and sourced - including it would be fine. ] (]) 12:37, 11 September 2023 (UTC)


::::::::{{Ping|JMF|Nø}} Well, as explained in our article, the only true period for the Easter dates is 5,700,000 years. I disagree that what I wrote is just a "mathematical artefact of no significance". The reason what I wrote works is that 152 years is a day short of two ]s, which means that the phase of the moon is more or less the same, and the fact that a Calippic cycle has four days more than a whole number of weeks means that two Calippic cycles minus 1 day is a whole number of weeks. So whenever the 152 years spans one year like 1800 where the Gregorian calendar drops a leap year, and there's also a lunar correction, then you get periods that follow exactly the same pattern, for 48 or 100 years. If the 152 years does not span a year like 1800 (for instance going from 1900 to 2052), then we have exactly two Calippic cycles, so the day of the week is off by 1. That gives periods where the pattern is almost the same. All this is of interest to mathematically minded people like me. I have no idea where to find a reference for all this, but why do we need a reference for something that can be easily checked? We don't need a reference in order to say that it's an interesting question, after all. I suggest that those of you who don't find it interesting stop reading it and go find something else to do in life rather than deleting the work of other people. ] (]) 16:20, 11 September 2023 (UTC)
:::::::::::The verifiable source is obviously the paper itself. ] (]) 15:03, 23 May 2015 (UTC)
:::::::::Eric Kvaalen asked "...but why do we need a reference for something that can be easily checked?" If a numerical curiosity is mentioned in several well-regarded sources, that hints that it's worth including in our article. If no reliable sources felt it was worth mentioning, it probably isn't worth mentioning. ] (]) 16:31, 11 September 2023 (UTC)
:::::::::{{tq|I suggest that those of you who don't find it interesting stop reading it and go find something else to do}} That could be addressed to our readership. This article isn't a personal blog existing for your self-indulgence. ] (]) 19:27, 11 September 2023 (UTC)


I hope it's clear from what I wrote yesterday that this is not a case of pareidolia. I have a question for Caligula, Claudius, and Nero: You say what I wrote is not interesting, and I suppose you are concerned for the disk space of Wikimedia. What if I find three μαρτῠ́ρους who will attest to finding that it is interesting? Is it still you who get to decide? ] (]) 07:09, 12 September 2023 (UTC)
::::::::::::Sorry to puncture your balloon, but as I already indicated above the blanked section is nowhere to be found in Lichtenberg (2003). How long do you want to keep on this farce? I can keep up just as long as you can. ] (]) 15:08, 23 May 2015 (UTC)
:You need to read ] (although "find" sounds like you also need to read ]). And don't you mean Caesar, Pompey and Crassus? ] (]) 07:17, 12 September 2023 (UTC)
::And you have to show a reliable source that considers this factoid to have any significance, specifically in respect of calculation of the date of Easter. --] (]) 15:04, 12 September 2023 (UTC)


:::It's Catch 22. There are three Caesars, or shall I call them watchful dragons, guarding this page to prevent any changes they don't agree with. If they revert you, you're stuck. You can't revert back or you get warnings of "edit wars". You can't ask someone else, or you get accused of canvasing. I have three friends who I think would agree with me that what I wrote was interesting, but I'm told that it doesn't matter. What the Caesars want is what happens. I'm told that I have to find a "reliable source" to say that it's interesting! Just another way of preserving the statum quo ante. Now I'll probably get a warning for arguing. ] (]) 06:54, 20 September 2023 (UTC)
:::::::::::::As your parachute deflates, you can ponder that there is no requirement that ideas should be reported in the precise words of the person who originates them.] (]) 15:20, 23 May 2015 (UTC)
::::No warning, but I am surprised that after 18 years and 10k edits on Misplaced Pages (I just checked) these very basic policy principles seem to be news to you. Do you really not know about ], ], ] and ]? ] (]) 07:00, 20 September 2023 (UTC)


:::::Yes, I know the cards are stacked against me. ] (]) 10:02, 20 September 2023 (UTC)
{{od}}The problem is that most of the numbers and years listed in the blanked section are nowhere mentioned in Lichtenberg's (2003) paper. Nor is the Synod of Whitby anywhere referred to in the same paper. How can you claim that your text is a selective rephrasing of Lichtenberg's paper? I am seriously beginning to doubt whether you have ever read the Lichtenberg paper you are claiming to cite. ] (]) 15:38, 23 May 2015 (UTC)
::::::Eric, no, the cards are not stacked against you, or to be more precise, they are stacked against any editor who tries to add original research or trivia. Let me repeat: all you need to do is to find "a reliable source that considers this factoid to have any significance, specifically in respect of calculation of the date of Easter". Consensus (or lack thereof) does not trump reliable sources. --] (]) 10:18, 20 September 2023 (UTC)
:::::::Well, I don't actually agree with that - ] says specifically otherwise. ] (]) 11:28, 20 September 2023 (UTC)
::::::::True but as it is a (very) hypothetical question, I didn't consider it necessary to qualify my response with details of the more advanced aspects of source quality and preponderance of expert opinion. We are nowhere near that stage; right now, we have no sources whatever that attach any significance to Eric's mathematical coincidence. --] (]) 12:08, 20 September 2023 (UTC)
::::::::But to be unambiguously clear: if Eric succeeds in producing citations that meet my test, I will change my !vote from 'oppose' to 'support'. "When the facts change, I change my mind. What do you do, sir?"{{mdash}}]. --] (]) 15:50, 20 September 2023 (UTC)
:::::::::There were three issues with , only one of which was lack of sourcing. The second is whether it's worth making the point. I could be swayed on that by sourcing but it would take more than ] to do that. But the third is the meandering blog-style ] would have to be converted into encyclopedic language which was considerably shorter (and which certainly doesn't begin with "One may wonder..."). ] (]) 20:34, 20 September 2023 (UTC)
::::::::::If it hasn't materialised by now, it isn't going to. My point was about the general principle. --] (]) 22:17, 20 September 2023 (UTC)


== If Astronomical Full Moon was used for Easter, instead of the Ecclesiastical Full Moon ==
:As I say, it doesn't have to be exact. To say that "most" of the years are different is not good enough. Please list specifically the years which you find to be different. ] (]) 15:44, 23 May 2015 (UTC)


If we use the Astronomical Full Moon to determine when Easter is, the Astronomical Full Moon dates would range from March 21 to April 19, as March 20 is often the date of the Equinox, the additional day (April 19) would need to be included as the lunar month on average is 29 days, 12 hours, 44 minutes, and 3 seconds long that extra 12 hours, 44 minutes and 3 seconds would need to be added onto April 19, so Easter would occasionally fall as late as April 26 under this rule, and if April 19 is on a Monday through Saturday, the date of Easter wouldn't change if the full moon were to be one day earlier (April 18).
::OK, which table or page lists the years 11800 and higher? Where is the Synod of Whitby mentioned? Where are the values for lunar jitter mentioned? Unless you can provide specific page numbers from Lichtenberg's (2003) paper mentioning these numbers, I can only conclude that it is unsourced. ] (]) 16:02, 23 May 2015 (UTC)


:::As I pointed out, Lichtenberg does the calculation over 10,000 years so you wouldn't expect to see years 11,800+ appearing in his data. You can still provide the data for earlier years. ] (]) 12:09, 24 May 2015 (UTC) Although the true Astronomical Equinox is March 19, March 20, and March 21 depending on leap years and time zones (but the equinox is most often on March 20), so the Astronomical Easter Full Moon would range from March 21 to April 19. ] (]) 20:51, 30 January 2024 (UTC)


== Incorrect date for Jewish Passover ==
::::So you finally admit that most of the numbers and years listed in the blanked section are not found in the Lichtenberg (2003) paper but are based on original research (probably yours?). I still seriously doubt whether you have actually read Lichtenberg's paper.


On the Hebrew calendar, passover starts on 15 Nisan, not 14 Nisan. ] (]) 13:14, 25 March 2024 (UTC)
::::As I became interested in the reason why you persist in having this section restored I had a closer look at the original edit on by , one of the known London-based sockpuppets of .


:It would help if you would provide a citation to a reliable source for this information, that makes it clear (1) what version of the Hebrew calendar the claim applies to and (2) includes the time of day. It's confusing because I understand that in some situations Hebrew days start in the evening while modern secular days start at midnight. Also, please quote the exact sentence you object to so we can find it in the article. ] (]) 17:30, 25 March 2024 (UTC)
::::Comparing the latter's editing behavior (and that of his numerous sockpuppets) with yours has been very insightful and revealing - it explains so much. ] (]) 12:57, 24 May 2015 (UTC)
::I assume that that Jonmlevinson is referring to the second sentence of #Background: {{tq|In the Hebrew ] calendar, Passover begins on the 14th day of ].}}
::I wonder if the intro to ] might give a clue? {{tq| It is conducted throughout the world on the eve of the 15th day of Nisan in the Hebrew calendar (i.e., at the start of the 15th; a Hebrew day begins at sunset). }} The "eve of the 15th day" is the 14th day, is it not? (That would imply that the Seder article is theologically wrong because formally it is conducted at the ''start'' of 15 Nisan, which to Gentiles is still the 14th for another six hours or so. To say "the eve of the 15th" seems rather inconsistent?) Either way, ]'s request #2 is critical. --] (]) 17:47, 25 March 2024 (UTC)
::I see we are not the first to encounter this conundrum () so we need at least to add an explanatory note. Right now, we don't even have a citation. --] (]) 18:38, 25 March 2024 (UTC)
:: is clearer. It explains that ] starts on 14 Nisan but Passover proper starts on the 15th. Clarification note definitely needed. --] (]) 18:43, 25 March 2024 (UTC)
:::I'm not sure how reliable that source is? Does anyone else make a distinction between Pesach and Passover? --] (]) 17:24, 26 March 2024 (UTC)
::I have revised that sentence so that it reads now
::{{quote|In the Hebrew ] calendar, Passover begins at twilight on the 14th day of ].<ref>{{Bibleverse|Exodus|12:18}}</ref><ref>{{Bibleverse|Leviticus|23:5}}</ref> }}
::I assume that this resolves the question. --] (]) 17:24, 26 March 2024 (UTC)


:::::What a load of rubbish! I drew attention to the "sockpuppet" issue earlier in this thread. The section was declared kosher five years ago so you have a high bar to overcome to remove it. You're creating a diversion by throwing mud around in the hope that some will stick. If you're not prepared to justify your position by detailing the "discrepancies" you allege you can be dismissed as just a troll. I object to people removing good content for spurious reasons. This subject was extensively discussed in the archives - I suppose Karl Palmen, Tom Peters and the rest are all sockpuppets as well. ] (]) 13:17, 24 May 2015 (UTC)


{{reflist talk}}
::::::Despite your whining you still have not provided a verifiable source for the blanked section - original research doesn't belong in WP. The blanked section never was 'declared kosher' five years ago as you claim - it was repeatedly removed after your sockpuppets tried to put it up again and again.


== Time Zone? ==
::::::If I were you I would also start worrying about your recent additions to ]. I have noticed that you have added quite a lot of unsourced text in recent days. If you do not start adding verifiable sources soon I will remove most of it - including the sections which appear to be original research. ] (]) 15:24, 24 May 2015 (UTC)


The very first paragraph summarises the "bottom line" of the lengthy article that follows as: ''Easter is celebrated on the first Sunday after the first full moon on or after 21 March.'' There is no reference to time zone. However, the "date of the first full moon" depends on the time zone; the last Pascal Full Moon, e.g., was on 25 March 2024 UTC but on March 24, 2024 Pacific Standard Time. Alternatively, if one would define Easter not via the "fixed approximation" of 21 March but instead by the actual Vernal Equinox, then the phrase "first Sunday after" would need to be augmented by a time zone specification, as is done by the reform proposed in 1997, which references Jerusalem astronomical time.
:::::::Nah, it was added once and there it stayed. I think we can assume from your reticence that the dates in the first ten thousand years are in agreement with those in the paper. ] (]) 15:36, 24 May 2015 (UTC)
I don't know what the actual current definition is, but it should be included in the article. ] (]) 12:00, 1 April 2024 (UTC)


:Perhaps it should be clarified, but there's no actual astronomy - or time zones - in the easter calculation; rather, there is a mathematical approximation that only deals with dates, not time of day, be it e.g. UTC or local, and not the exact time of the equinox. The text mentinos that 21 March is an approximation to the equinox, but fails to mention that the date of the full moon is also an approximation. Perhaps ''the first full moon on or after 21 March'' should be ''a date for the first full moon on or after the spring equinox on the Northern hemisphere, calculated using certain approximations''? ] (]) 14:02, 1 April 2024 (UTC)
::::::::Why don't you check yourself - you claim to have read the Lichtenberg paper. ] (]) 15:43, 24 May 2015 (UTC)
::None of the above. It is the ] (within a day or so of the astronomic full moon) and 21 March (usually one day after the equinox in the Gregorian calendar, 14 days after using the Julian calendar). Bede got it wrong 1500 years ago and people still repeat it. There is no satisfactory short description, afaics. ] (]) 15:32, 1 April 2024 (UTC)
:::It '''is''' a cartain mathematical approximation to the first Sunday after the first full moon after the equinox -- but it is not a good approximation.
:::* Equinox is appoximated as March 21 (let's call that approximation a1).
:::* The full moons are approximated too (let's call that a2) -- and may be a day (or two?) off because of a2, or about four weeks off because of a1.
:::* Finally, the Sunday -- well, there is not a third approximation here; we ''do'' know the days of the week -- but if the full moon is a day off because of a2, or just a few hours, the Sunday may be a week off, and/or it may be four weeks of because of a1.
:::However, to say whether it in a given year and location is correct or it is one, three, four or five weeks too early or too late (I suppose all those are possible - perhaps two or six weeks early or late as well), we'd need to know the ''exact'' "first Sunday after the first full moon after the equinox", and there are several ambiguities in that phrase that would have to be resolved before we could say that; the question about time zones could one of them.
:::Despite all the problems with the approximations, I suppose the computus does in fact most years, most locations, and with most sensible resolutions to the ambiguities of the phrase, give us the exact "first Sunday after the first full moon after the equinox". ] (]) 16:21, 1 April 2024 (UTC)


== Case of ''paschal'' ==
:::::::::Information like that is not something you would commit to memory. ] (]) 09:00, 27 May 2015 (UTC)


The term ''paschal'' is frequently used in this article, but its initial letter is sometimes uppercase and sometimes lowercase. When it is in uppercase, sometimes it is part of a phrase that could be treated like a proper name (just as months and days of the week are), e.g. ''Paschal Full Moon'' or ''Paschal Month''. It should be spelled consistently throughout the article. I have a minor preference for uppercasing, but really do not care that much. The dictionaries I have consulted mostly have the adjective in lowercase but also have a varying list of titlecased proper names starting with it. — ] ] 10:14, 3 December 2024 (UTC)
::::::::::You should have kept notes. If you had access to the Lichtenberg paper five years ago, you should be able access it again now. ] (]) 09:49, 27 May 2015 (UTC)


:I have a slight preference for lowercase, but the main thing is uniformity throughout the article. If the sources consistently capitalize "Paschal Full Moon", so should this article. ] (]) 16:26, 3 December 2024 (UTC)
:::::::::::This is typical of your attitude. Looking at your editing history I see you've tried this trick before. When someone wants to do an end run around Misplaced Pages policy it's they who have to do the legwork. We have a verified stable version which you want to change. In the previous incident you were trying to skate round ]. Editors pointed to sources which they wanted to include in an article and you pointed to a book which you claimed supported your viewpoint. Asked to support this by quoting the relevant passage you said you didn't have a copy and would order it through the library if the editor used "the magic word". Later, when an editor referred to the book you quoted from it instantly, thus proving that you had had a copy of it all the time. You exhorted the editor to get a copy of the book so as to quote from it "to prove wrong." That's not what good faith, collegial editing is all about. The incident related to an attempt by you to exclude the other editors' sources from a description of a picture of Muhammad. You have this picture on your web profile. You are arguably obsessed with it. ] (]) 10:55, 27 May 2015 (UTC)
::I don't think the sourcves are overall more consistent than this article internally. — ] ] 13:39, 4 December 2024 (UTC)
:::In that case, ] advises lowercase: "only words and phrases that are consistently capitalized in a substantial majority of independent, reliable sources are capitalized in Misplaced Pages". ] (]) 16:00, 4 December 2024 (UTC)

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Whether the pattern repeats

@Tom Peters: Tom, what do you think? I added the following paragraph:

One may wonder whether the pattern of dates of Easter repeats. As can be verified in a table of the dates, the dates from 1948 to 2047 are the same as for those 152 years later (2100 to 2199). This period of 152 years is one day short of two Calippic cycles, and is a whole number of weeks. Also the dates for 1800 to 1899 are the same as those for 152 years later (1952 to 2051) in all but 11 cases. The epacts differ by 1, as do the dates of the ecclesiastical 14th of Nisan, but usually the next Sunday falls on the same date. It is possible to have the same dates for the 14th of Nisan and on the same day of the week for other intervals, but since the golden number is not the same, this situation lasts for less than 19 years at a time. For example, the 100-year period 1980-2079 is almost repeated 220 years later (2200-2299), but with six cases that don't agree. An interval of 18,000 years achieves this in some cases
Footnote (which I can't seem to put here in the talk page): It is easy to verify that this occurs if the interval contains 58 lunar corrections and the golden number of the first of the two years in question is less than 13, or if there are 57 lunar corrections and the first golden number is greater than 12. In either case, these cancel out the 135 solar corrections.
and is also a whole number of 400-year Gregorian cycles, but again the golden number will be different, so the pattern does not repeat exactly.

Five minutes later Jc3s5h reverted it, saying that it's a "wall of text" that doesn't answer the question I asked at the beginning -- whether the pattern repeats, and he says it repeats in 5.7 million years. Well of course, we all know that. But does that justify reverting my edit? The question I mean is whether the pattern repeats for a while, like a century, and the answer is yes. I think it's quite interesting, and should be in the article. Eric Kvaalen (talk) 19:25, 10 September 2023 (UTC)

I was going to revert it and Jc3s5h beat me to it by minutes. It reads far too much like a blog post, beginning with "One may wonder whether the pattern of dates of Easter repeats" which is exceedingly unecyclopedic. It was also too far too long for the thoughts expressed. Arguably it works better as a talk page post here to open a discussion on whether/how to express your thoughts. DeCausa (talk) 19:33, 10 September 2023 (UTC)
So why don't you modify the wording instead of deleting the whole thing?? I wish you people would stop complaining every time someone puts something interesting into an article. Nobody is forcing you to read it, after all! Other people might want to read it. Eric Kvaalen (talk) 20:34, 10 September 2023 (UTC)
I didn't delete it. But if I had I would reject your point because it's not my job to correct your failings. Why should I put effort into dragging out some sort of value in your edit when I can't see any? It's not interesting and it shouldn't be in the article. DeCausa (talk) 20:37, 10 September 2023 (UTC)
You and Jc3s5h act like Caesar watching the gladiators, and giving a thumbs up or thumbs down. Who made you the judges? I think it's very interesting that the pattern repeats exactly or almost exactly over periods of 100 years, at certain intervals. Another case I didn't put is that 1700-1747 is exactly the same as 1852-1899. One would think that people interested in Easter would show a bit of Christian charity. Eric Kvaalen (talk) 09:01, 11 September 2023 (UTC)
In that case, we may as well have a triumvirate. I'd have reverted it too, per WP:TRIVIA. It is a mathematical artefact of no significance. A form of pareidolia. --𝕁𝕄𝔽 (talk) 09:22, 11 September 2023 (UTC) revised 09:27, 11 September 2023 (UTC)
I love a thread where pareidolia is an issue. :) DeCausa (talk) 10:00, 11 September 2023 (UTC)
I think the issue is interesting enough that if a good source (other than the dates themselves) can be found, and if it can be stated briefly and clearly, it may be relevant for the article -- but it is up to user:Eric Kvaalen or others who want to include it to demonstrate that. In the Gregorian calendar there is a period-4 stemming from leap years and a period-7 stemming from days of the week, combining into a period-28 (not related to churches, Easter or holidays) so that e.g. from 1901 to 2099, the calendar for any two years separated by a multiple of 28 years is the same (all Mondays fall on the same dates, etc.) - but the "missing" leap years in 1700, 1800, 1900, 2100, 2200 ect. spoil the fun. Incidentally, the true period-400 in the leap years coincide with a whole number of weeks (400*365 + 100 - 3 = 146097 days = 20871 weeks), so there is a true, perpetual period-400 in the Gregorian calendar. -- Is that relevant here? No, but if similar neat patterns could be descirbed for dates of Easter - and sourced - including it would be fine. (talk) 12:37, 11 September 2023 (UTC)
@JMF and : Well, as explained in our article, the only true period for the Easter dates is 5,700,000 years. I disagree that what I wrote is just a "mathematical artefact of no significance". The reason what I wrote works is that 152 years is a day short of two Calippic cycles, which means that the phase of the moon is more or less the same, and the fact that a Calippic cycle has four days more than a whole number of weeks means that two Calippic cycles minus 1 day is a whole number of weeks. So whenever the 152 years spans one year like 1800 where the Gregorian calendar drops a leap year, and there's also a lunar correction, then you get periods that follow exactly the same pattern, for 48 or 100 years. If the 152 years does not span a year like 1800 (for instance going from 1900 to 2052), then we have exactly two Calippic cycles, so the day of the week is off by 1. That gives periods where the pattern is almost the same. All this is of interest to mathematically minded people like me. I have no idea where to find a reference for all this, but why do we need a reference for something that can be easily checked? We don't need a reference in order to say that it's an interesting question, after all. I suggest that those of you who don't find it interesting stop reading it and go find something else to do in life rather than deleting the work of other people. Eric Kvaalen (talk) 16:20, 11 September 2023 (UTC)
Eric Kvaalen asked "...but why do we need a reference for something that can be easily checked?" If a numerical curiosity is mentioned in several well-regarded sources, that hints that it's worth including in our article. If no reliable sources felt it was worth mentioning, it probably isn't worth mentioning. Jc3s5h (talk) 16:31, 11 September 2023 (UTC)
I suggest that those of you who don't find it interesting stop reading it and go find something else to do That could be addressed to our readership. This article isn't a personal blog existing for your self-indulgence. DeCausa (talk) 19:27, 11 September 2023 (UTC)

I hope it's clear from what I wrote yesterday that this is not a case of pareidolia. I have a question for Caligula, Claudius, and Nero: You say what I wrote is not interesting, and I suppose you are concerned for the disk space of Wikimedia. What if I find three μαρτῠ́ρους who will attest to finding that it is interesting? Is it still you who get to decide? Eric Kvaalen (talk) 07:09, 12 September 2023 (UTC)

You need to read WP:CONSENSUS (although "find" sounds like you also need to read WP:CANVASS). And don't you mean Caesar, Pompey and Crassus? DeCausa (talk) 07:17, 12 September 2023 (UTC)
And you have to show a reliable source that considers this factoid to have any significance, specifically in respect of calculation of the date of Easter. --𝕁𝕄𝔽 (talk) 15:04, 12 September 2023 (UTC)
It's Catch 22. There are three Caesars, or shall I call them watchful dragons, guarding this page to prevent any changes they don't agree with. If they revert you, you're stuck. You can't revert back or you get warnings of "edit wars". You can't ask someone else, or you get accused of canvasing. I have three friends who I think would agree with me that what I wrote was interesting, but I'm told that it doesn't matter. What the Caesars want is what happens. I'm told that I have to find a "reliable source" to say that it's interesting! Just another way of preserving the statum quo ante. Now I'll probably get a warning for arguing. Eric Kvaalen (talk) 06:54, 20 September 2023 (UTC)
No warning, but I am surprised that after 18 years and 10k edits on Misplaced Pages (I just checked) these very basic policy principles seem to be news to you. Do you really not know about WP:CONSENSUS, WP:CANVASS, WP:V and WP:DUE? DeCausa (talk) 07:00, 20 September 2023 (UTC)
Yes, I know the cards are stacked against me. Eric Kvaalen (talk) 10:02, 20 September 2023 (UTC)
Eric, no, the cards are not stacked against you, or to be more precise, they are stacked against any editor who tries to add original research or trivia. Let me repeat: all you need to do is to find "a reliable source that considers this factoid to have any significance, specifically in respect of calculation of the date of Easter". Consensus (or lack thereof) does not trump reliable sources. --𝕁𝕄𝔽 (talk) 10:18, 20 September 2023 (UTC)
Well, I don't actually agree with that - WP:ONUS says specifically otherwise. DeCausa (talk) 11:28, 20 September 2023 (UTC)
True but as it is a (very) hypothetical question, I didn't consider it necessary to qualify my response with details of the more advanced aspects of source quality and preponderance of expert opinion. We are nowhere near that stage; right now, we have no sources whatever that attach any significance to Eric's mathematical coincidence. --𝕁𝕄𝔽 (talk) 12:08, 20 September 2023 (UTC)
But to be unambiguously clear: if Eric succeeds in producing citations that meet my test, I will change my !vote from 'oppose' to 'support'. "When the facts change, I change my mind. What do you do, sir?"—Paul Samuelson. --𝕁𝕄𝔽 (talk) 15:50, 20 September 2023 (UTC)
There were three issues with this edit, only one of which was lack of sourcing. The second is whether it's worth making the point. I could be swayed on that by sourcing but it would take more than one rogue source to do that. But the third is the meandering blog-style WP:WALLOFTEXT would have to be converted into encyclopedic language which was considerably shorter (and which certainly doesn't begin with "One may wonder..."). DeCausa (talk) 20:34, 20 September 2023 (UTC)
If it hasn't materialised by now, it isn't going to. My point was about the general principle. --𝕁𝕄𝔽 (talk) 22:17, 20 September 2023 (UTC)

If Astronomical Full Moon was used for Easter, instead of the Ecclesiastical Full Moon

If we use the Astronomical Full Moon to determine when Easter is, the Astronomical Full Moon dates would range from March 21 to April 19, as March 20 is often the date of the Equinox, the additional day (April 19) would need to be included as the lunar month on average is 29 days, 12 hours, 44 minutes, and 3 seconds long that extra 12 hours, 44 minutes and 3 seconds would need to be added onto April 19, so Easter would occasionally fall as late as April 26 under this rule, and if April 19 is on a Monday through Saturday, the date of Easter wouldn't change if the full moon were to be one day earlier (April 18).

Although the true Astronomical Equinox is March 19, March 20, and March 21 depending on leap years and time zones (but the equinox is most often on March 20), so the Astronomical Easter Full Moon would range from March 21 to April 19. 2603:6011:E00:4C41:0:0:0:100D (talk) 20:51, 30 January 2024 (UTC)

Incorrect date for Jewish Passover

On the Hebrew calendar, passover starts on 15 Nisan, not 14 Nisan. Jonmlevinson (talk) 13:14, 25 March 2024 (UTC)

It would help if you would provide a citation to a reliable source for this information, that makes it clear (1) what version of the Hebrew calendar the claim applies to and (2) includes the time of day. It's confusing because I understand that in some situations Hebrew days start in the evening while modern secular days start at midnight. Also, please quote the exact sentence you object to so we can find it in the article. Jc3s5h (talk) 17:30, 25 March 2024 (UTC)
I assume that that Jonmlevinson is referring to the second sentence of #Background: In the Hebrew lunisolar calendar, Passover begins on the 14th day of Nisan.
I wonder if the intro to Passover Seder might give a clue? It is conducted throughout the world on the eve of the 15th day of Nisan in the Hebrew calendar (i.e., at the start of the 15th; a Hebrew day begins at sunset). The "eve of the 15th day" is the 14th day, is it not? (That would imply that the Seder article is theologically wrong because formally it is conducted at the start of 15 Nisan, which to Gentiles is still the 14th for another six hours or so. To say "the eve of the 15th" seems rather inconsistent?) Either way, User:Jc3s5h's request #2 is critical. --𝕁𝕄𝔽 (talk) 17:47, 25 March 2024 (UTC)
I see we are not the first to encounter this conundrum (Why Is Passover on Nissan 15, Not Nissan 14?) so we need at least to add an explanatory note. Right now, we don't even have a citation. --𝕁𝕄𝔽 (talk) 18:38, 25 March 2024 (UTC)
This source is clearer. It explains that Pesach starts on 14 Nisan but Passover proper starts on the 15th. Clarification note definitely needed. --𝕁𝕄𝔽 (talk) 18:43, 25 March 2024 (UTC)
I'm not sure how reliable that source is? Does anyone else make a distinction between Pesach and Passover? --𝕁𝕄𝔽 (talk) 17:24, 26 March 2024 (UTC)
I have revised that sentence so that it reads now

In the Hebrew lunisolar calendar, Passover begins at twilight on the 14th day of Nisan.

I assume that this resolves the question. --𝕁𝕄𝔽 (talk) 17:24, 26 March 2024 (UTC)


References

  1. Exodus 12:18
  2. Leviticus 23:5

Time Zone?

The very first paragraph summarises the "bottom line" of the lengthy article that follows as: Easter is celebrated on the first Sunday after the first full moon on or after 21 March. There is no reference to time zone. However, the "date of the first full moon" depends on the time zone; the last Pascal Full Moon, e.g., was on 25 March 2024 UTC but on March 24, 2024 Pacific Standard Time. Alternatively, if one would define Easter not via the "fixed approximation" of 21 March but instead by the actual Vernal Equinox, then the phrase "first Sunday after" would need to be augmented by a time zone specification, as is done by the reform proposed in 1997, which references Jerusalem astronomical time. I don't know what the actual current definition is, but it should be included in the article. MsohniCam (talk) 12:00, 1 April 2024 (UTC)

Perhaps it should be clarified, but there's no actual astronomy - or time zones - in the easter calculation; rather, there is a mathematical approximation that only deals with dates, not time of day, be it e.g. UTC or local, and not the exact time of the equinox. The text mentinos that 21 March is an approximation to the equinox, but fails to mention that the date of the full moon is also an approximation. Perhaps the first full moon on or after 21 March should be a date for the first full moon on or after the spring equinox on the Northern hemisphere, calculated using certain approximations? (talk) 14:02, 1 April 2024 (UTC)
None of the above. It is the Paschal Moon (within a day or so of the astronomic full moon) and 21 March (usually one day after the equinox in the Gregorian calendar, 14 days after using the Julian calendar). Bede got it wrong 1500 years ago and people still repeat it. There is no satisfactory short description, afaics. 𝕁𝕄𝔽 (talk) 15:32, 1 April 2024 (UTC)
It is a cartain mathematical approximation to the first Sunday after the first full moon after the equinox -- but it is not a good approximation.
  • Equinox is appoximated as March 21 (let's call that approximation a1).
  • The full moons are approximated too (let's call that a2) -- and may be a day (or two?) off because of a2, or about four weeks off because of a1.
  • Finally, the Sunday -- well, there is not a third approximation here; we do know the days of the week -- but if the full moon is a day off because of a2, or just a few hours, the Sunday may be a week off, and/or it may be four weeks of because of a1.
However, to say whether it in a given year and location is correct or it is one, three, four or five weeks too early or too late (I suppose all those are possible - perhaps two or six weeks early or late as well), we'd need to know the exact "first Sunday after the first full moon after the equinox", and there are several ambiguities in that phrase that would have to be resolved before we could say that; the question about time zones could one of them.
Despite all the problems with the approximations, I suppose the computus does in fact most years, most locations, and with most sensible resolutions to the ambiguities of the phrase, give us the exact "first Sunday after the first full moon after the equinox". (talk) 16:21, 1 April 2024 (UTC)

Case of paschal

The term paschal is frequently used in this article, but its initial letter is sometimes uppercase and sometimes lowercase. When it is in uppercase, sometimes it is part of a phrase that could be treated like a proper name (just as months and days of the week are), e.g. Paschal Full Moon or Paschal Month. It should be spelled consistently throughout the article. I have a minor preference for uppercasing, but really do not care that much. The dictionaries I have consulted mostly have the adjective in lowercase but also have a varying list of titlecased proper names starting with it. — Christoph Päper 10:14, 3 December 2024 (UTC)

I have a slight preference for lowercase, but the main thing is uniformity throughout the article. If the sources consistently capitalize "Paschal Full Moon", so should this article. Indefatigable (talk) 16:26, 3 December 2024 (UTC)
I don't think the sourcves are overall more consistent than this article internally. — Christoph Päper 13:39, 4 December 2024 (UTC)
In that case, MOS:CAPS advises lowercase: "only words and phrases that are consistently capitalized in a substantial majority of independent, reliable sources are capitalized in Misplaced Pages". Indefatigable (talk) 16:00, 4 December 2024 (UTC)
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