# Easter date always changes- what's up with that? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 25, 2005, 1:03am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123 "2005-03-25T01:03:01Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![LadySybil](https://avatars.discourse-cdn.com/v4/letter/l/c89c15/32.png) [@LadySybil](https://boards.straightdope.com/u/LadySybil)\ **Post date:** [March 25, 2005, 1:03am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/1 "2005-03-25T01:03:01Z")
So I was helping a customer at work today, and we were talking about how busy it was. I told her that the store is always uber-busy right before Easter. “Hey, how come Easter always seems to change dates each year?” she asked. “I just realized that.” IIRC, she’s right. Why do we have an exact date to celebrate the birth of Jesus Christ (December 25th\*), but not an exact date to commemorate His crucifixion and resurrection? Is the calendar’s date of Easter affected by the phases of the moon? Is it just the last sunday of March? Bonus cool points if you can tell me how we got Easter bunnies, Peeps and colored eggs from the death of a worshiped guy and his sudden popping out of a burial cave. \*Disclaimer: I know that the given date of Christmas probably isn’t really the day He was born, and that the church probably pegged the commemoration on 12-25 to smack down solstice festivals or something. ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [March 25, 2005, 1:11am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/2 "2005-03-25T01:11:37Z")
> [@LadySybil](#): > > Is the calendar’s date of Easter affected by the phases of the moon? You got it. > [@](#): > > Is it just the last sunday of March? Easter falls in April more often than not. From [this site](http://aa.usno.navy.mil/faq/docs/easter.html) comes this: > [@](#): > > The ecclesiastical rules are: > > ``` > * Easter falls on the first Sunday following the first ecclesiastical full moon that occurs on or after the day of the vernal equinox; > * this particular ecclesiastical full moon is the 14th day of a tabular lunation (new moon); and > * the vernal equinox is fixed as March 21. > > ``` > > resulting in that Easter can never occur before March 22 or later than April 25. The Gregorian dates for the ecclesiastical full moon come from the Gregorian tables. Therefore, the civil date of Easter depends upon which tables - Gregorian or pre-Gregorian - are used. The western (Roman Catholic and Protestent) Christian churches use the Gregorian tables; many eastern (Orthodox) Christian churches use the older tables based on the Julian Calendar. Basically, if they kept the date the same, next year we’d have Good Saturday… ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [March 25, 2005, 1:22am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/3 "2005-03-25T01:22:15Z")
Easter’s more in line with pagan celebrations of Spring that the original church elders would ever have cared to admit. ---
**Author:** ![Fretful\_Porpentine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fretful_porpentine/32/2873_2.png) [@Fretful\_Porpentine](https://boards.straightdope.com/u/Fretful_Porpentine)\ **Post date:** [March 25, 2005, 1:22am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/4 "2005-03-25T01:22:22Z")
There’s an _ecclesiastical_ full moon, distinct from an astronomical one? Huh. I did not know that. :: tries to clear head of images of Ecclesiastical Werewolves running around in mitres and long robes :: ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [March 25, 2005, 1:25am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/5 "2005-03-25T01:25:30Z")
> [@Fretful Porpentine](#): > > There’s an _ecclesiastical_ full moon, distinct from an astronomical one? Huh. I did not know that. > > :: tries to clear head of images of Ecclesiastical Werewolves running around in mitres and long robes :: [They’re just imagining things.](http://www.sizes.com/time/moon_eccles.htm) ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [March 25, 2005, 1:39am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/6 "2005-03-25T01:39:28Z")
> [@Ice Wolf](#): > > Easter’s more in line with pagan celebrations of Spring that the original church elders would ever have cared to admit. I think the _original_ church elders would have been remarkably frank about that, if you’d managed to talk to one of them off the record. The later (and current) ones are the lot who’d gloss over it. The original guys were just good marketers who had the sense to introduce Christianity gradually by retaining many of the customs people were comfortable with. The whole fertility thing of Spring was a stroke of good luck for the early church as they could segue that into the resurrection pretty seamlessly. ---
**Author:** ![Waterman](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Waterman](https://boards.straightdope.com/u/Waterman)\ **Post date:** [March 25, 2005, 2:28am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/7 "2005-03-25T02:28:44Z")
> [@LadySybil](#): > > So I was helping a customer at work today, and we were talking about how busy it was. I told her that the store is always uber-busy right before Easter. > > “Hey, how come Easter always seems to change dates each year?” she asked. “I just realized that.” > > IIRC, she’s right. Why do we have an exact date to celebrate the birth of Jesus Christ (December 25th\*), but not an exact date to commemorate His crucifixion and resurrection? Is the calendar’s date of Easter affected by the phases of the moon? Is it just the last sunday of March? … There is a fascinating, and very scholarly though somewhat tongue-in-cheek, book titled _Calendar - Humanity’s Epic Struggle to Determine a True and Accurate Year_, by David Ewing Duncan that devotes an entire chapter to this subject. First and foremost it seems the problem was that no one who had witnessed Christ’s death and resurrection had thought to jot down a date :smack: :smack: :smack: The second complication is the fact that Christ’s resurrection occurred during the Jewish Passover, which is dated according to the phases of the moon in the Jewish calendar. This means that the dates for both Passover and Easter drifts against the solar calendar. Lest you think that the “Church” was lacking in mathematical skills, a Council was held in 325, under the guidance of Constantine, in the City of Nicaea, to determine (amomg other items) the date that Easter would fall on. They devised an algorithm to calculate the date; however, the Julian calendar was 11 minutes off each year and serious problems arose later requiring the adjustment from the Julian to Gregorian calendars (another fascinating subject). Correcting the original Nicaean algorithm for the modern calendar you can use the following formulae to calculate past and future dates for Easter (taken from Duncan’s book): a= year%/19 b= year/100 year%100 d=b/4 e=b%4 f=(b+8)/25 g=(b-f+1)/3 h=(19_a+b-d-g+15)%30 i=c/4 k=c%4 l=(32+2_e+2_i-h-k)%7 m=(a+11_h+22\*l)/451 Easter Month=(h+1-7\*m+114/31) 3=March and 4=April p=(h+1-7\*m+114)%31 Easter date= p+1 (date in Easter Month) where /=division neglecting remainder %= division keeping only the remainder \*=multiply **Who said the Catholic church doesn’t have a sense of humour!** ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [March 25, 2005, 2:35am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/8 "2005-03-25T02:35:14Z")
Umm… **Ice Wolf** , I think it’s a bit unfair to claim that Easter is set to correspond to pagan rights of spring. Unless you view Judaism as a form of Paganism. Easter is set by the date for Passover. And Passover is set by the Hebrew calendar. Which is lunar in nature, not solar. ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [March 25, 2005, 2:38am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/9 "2005-03-25T02:38:57Z")
Eggs? Rabbits? Sounds like a fertility festival to me. It may well be genuinely tied to Judaism, but that didn’t stop the early church from prettying it up with pagan rituals for European consumption… ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [March 25, 2005, 2:40am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/10 "2005-03-25T02:40:55Z")
Oh, I can’t and don’t argue that. Certainly the concurrence was used for evangelical purposes. To claim that’s why Easter happens when it does seems to be putting the cart before the horse. ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [March 25, 2005, 3:26am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/11 "2005-03-25T03:26:15Z")
> [@OtakuLoki](#): > > Umm… **Ice Wolf** , I think it’s a bit unfair to claim that Easter is set to correspond to pagan rights of spring. Unless you view Judaism as a form of Paganism. > > Easter is set by the date for Passover. > > And Passover is set by the Hebrew calendar. Which is lunar in nature, not solar. So, you’re saying that Easter is calculated by when Passover is, rather than computations as to how many moons there are from the beginning of the year to say, roughly, _spring_? I see Passover’s first night is late April this year. Can’t see the Easter connection, meself. Why would it be unfair to associate the likenesses of Easter with one faith, and not another? ---
**Author:** ![JThunder](https://avatars.discourse-cdn.com/v4/letter/j/e95f7d/32.png) [@JThunder](https://boards.straightdope.com/u/JThunder)\ **Post date:** [March 25, 2005, 4:22am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/12 "2005-03-25T04:22:38Z")
Yes, it does get confusing. It’s especially confusing when Easter falls on a Tuesday or a Wednesday. I hate it when that happens. ---
**Author:** ![Good\_Egg](https://avatars.discourse-cdn.com/v4/letter/g/96bed5/32.png) [@Good\_Egg](https://boards.straightdope.com/u/Good_Egg)\ **Post date:** [March 25, 2005, 4:40am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/13 "2005-03-25T04:40:10Z")
Easter is a pagan festival to replace the real resurrection, which was on Passover. It was for the "godess"Astarte, or Astorth. I will have to look up the reference and get back. Some “god” had a pig and thats why the ham eating also. Bunnies and eggs have nothing to do with Jesus, just like trees,etc. have nothing to do with Christ’s birth. Doeds mass mean birth anyway? I thought it was something to be had when someone died, which would make merry christmas to mean glad Christ is dead. ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [March 25, 2005, 4:49am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/14 "2005-03-25T04:49:03Z")
Don’t forget [Oestre](http://illuminatedperceptions.com/oestre.htm), **Good Egg** (apt username for this thread, BTW!) 🙂 ---
**Author:** ![Good\_Egg](https://avatars.discourse-cdn.com/v4/letter/g/96bed5/32.png) [@Good\_Egg](https://boards.straightdope.com/u/Good_Egg)\ **Post date:** [March 25, 2005, 4:49am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/15 "2005-03-25T04:49:52Z")
[http://www.lasttrumpetministries.org/tracts/tract1.html](http://www.lasttrumpetministries.org/tracts/tract1.html) ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [March 25, 2005, 5:51am UTC](https://boards.straightdope.com/t/easter-date-always-changes-whats-up-with-that/296123/16 "2005-03-25T05:51:58Z")
> [@Good Egg](#): > > Doeds mass mean birth anyway? I thought it was something to be had when someone died, which would make merry christmas to mean glad Christ is dead. Mass is the term that Catholics use for their church services (I’m sure a Catholic will come along to say what’s neccesary to make it a mass). Christmas is just the mass celebrated to celebrate Christ’s birth. And your link mixes up Babylonian, Canaanite, Egyptian, and Hebrew myth there, I think. And in Babylonian myth, Tammuz is the brother and husband of Ishtar, not her son. The Babylonian sun god isn’t Baal. It’s Shamash. Baal was a Canaanite god of fertility, and sometimes of the sun. Nimrod, of course, comes from Hebrew legend, where he’s the son of Cush, and a “mighty hunter”, who founded Nineveh and began the Assyrian empire. He also is said to have persecuted and tried to kill the patriarch Abraham for refusing to worship idols.