The perpetual calendar
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From: Mike Dworetsky on 21 Feb 2010 08:30 Androcles wrote: > "Mike Dworetsky" <platinum198(a)pants.btinternet.com> wrote in message > news:EsednSDu7Im2jB3WnZ2dnUVZ7sGdnZ2d(a)bt.com... >> Androcles wrote: >>> "Mike Dworetsky" <platinum198(a)pants.btinternet.com> wrote in message >>> news:jc6dnUEvCLDSC-LWnZ2dnUVZ8tOdnZ2d(a)bt.com... >>>> Yusuf B Gursey wrote: >>>>> On Feb 19, 4:34 am, James Hogg <Jas.H...(a)gOUTmail.com> wrote: >>>>>> John Atkinson wrote: >>>>>>> Halmyre wrote: >>>>>>>> On 19 Feb, 04:58, "Ray O'Hara" <raymond-oh...(a)hotmail.com> >>>>>>>> wrote: >>>>>>>>> "Andrew Usher" <k_over_hb...(a)yahoo.com> wrote in message >>>>>> >>>>>>>>> news:65e2a2e7-1aef-4872-97a7-360fa6a10a6a(a)q21g2000yqm.googlegroups.com... >>>>>> >>>>>>>>>> Owing to the inconveniences which attend the shifting of the >>>>>>>>>> calendar, and attempting in passing to create a more perfect >>>>>>>>>> Church calendar, I say the following: 1. That Christmas day >>>>>>>>>> should be fixed to a Sunday, and this should be the Sunday >>>>>>>>>> between Dec. 21 and 27, and that in all civilised countries >>>>>>>>>> the Monday should be considered a holiday, or the Saturday >>>>>>>>>> if not normally. 2. That similarly Easter day should be >>>>>>>>>> fixed to the Sunday which is 15 weeks following Christmas. >>>>>>>>>> 3. That the leap year rule be changed to have a leap year >>>>>>>>>> occur every fourth save that it be delayed when the leap >>>>>>>>>> year would start on a Thursday, and that this gives 7 leap >>>>>>>>>> years in every 29, which is near enough. 4. That the >>>>>>>>>> perpetual calendar can be made, by considering the first day >>>>>>>>>> of the year of weeks to occur on the Sunday after the >>>>>>>>>> Assumption, and if this is the first possible calendar day, >>>>>>>>>> it is called week 1, and otherwise week 2, and every year >>>>>>>>>> runs through week 53. And this calendar ensures that >>>>>>>>>> everything can be fixed to a day of a certain week, in >>>>>>>>>> particular the American Thanksgiving must be made 31 days >>>>>>>>>> before Christmas. 6. This is surely the best possible >>>>>>>>>> arrangement that can be made, without disturbing the cycle >>>>>>>>>> of weeks or that of calendar days inherited from the Romans. >>>>>>>>>> Andrew Usher >>>>>>>>> The calendar has several sources, not just the Rome and the >>>>>>>>> onewe habe in fine as it is >>>>>>>> I just wish they'd settle on a date for Easter and be done with >>>>>>>> it. >>>>>> >>>>>>> But, the whole point of Easter is that it has a full moon! You >>>>>>> might as well scrap the whole thing otherwise. Or are you >>>>>>> suggesting that we only take holidays at Easter every four years >>>>>>> or so, when your �settled� date just happens to correspond with >>>>>>> the right lunar phase? >>>>>> >>>>>> My Book of Common Prayer makes things easy by pointing out that >>>>>> "the moon referred to in the definition of Easter Day is not the >>>>>> actual moon of the heavens, but the Calendar Moon, or Moon of the >>>>>> Lunar Cycle, which is counted as full on its fourteenth day, >>>>>> reckoned from the day of the Calendar New Moon inclusive." Also, >>>>>> in a Bissextile Year "the number of Sundays after Epiphany will >>>>>> be the same, as if Easter Day had fallen one day later than it >>>>>> really does." >>>>> >>>>> the Orthodox (Eastern) churches have a slightly different system. >>>>> dunno exactly what it is. >>>>> >>>>> http://en.wikipedia.org/wiki/Easter >>>>> >>>>> Easter >>>> >>>> Orthodox Easter and other events are based on the Julian Calendar >>>> (one year = 365.25 days), while Catholic and Protestant practice >>>> follows the Gregorian calendar (one year = 365.2425 days plus the >>>> 1582 dropping of 10 days). Over several centuries, the date of the >>>> spring equinox has drifted away from March 21 in the Orthodox >>>> calendar. The two religious systems have different methods for >>>> calculating >>>> Easter within their own calendars. >>>> >>>> Do a Google search for "calendar FAQ". >>>> >>> http://www.youtube.com/watch?v=VsD2Nku6Zqo >>> Over two millennia, the date of the spring equinox has drifted by a >>> month. >> >> Over 2000 years, the calendrical difference of 0.0075 d/yr adds up >> to 15 days. > > >> In 1582, a correction of 10 days was done because the original >> agreement for the date of Easter was made not on AD1 but in AD325 at >> the Council of Nicea, so the accumulation over 1257 years was 9.4 >> days. I'm not certain why they dropped 10 days instead of 9; Ah. The "true" accumulated error is 1 day every 128 years, so (1582-325)/128 = 9.82 or in whole numbers, 10 days. Compared to the Gregorian reckoning, in that time interval the adjustment would be (1582-325)/125 = 10.06 days, where the factor 125 years is the interval over which the Gregorian and Julian calendars would differ by 1.0 days. >> possibly because 1600 would not be a Gregorian leap year? Or >> possibly because the most prevalent date was already pretty much set >> by around AD200? > 1 lunar month = 29.53059 days > "And the days of Methuselah were nine hundred sixty and nine years: > and he died." -- Genesis 5:27 > 969 lunar months = 74.5 years. If I were you I'd be very cautious of > literal translations of archaic timekeeping by the bell, book and > candle brigade. > http://www.glyphweb.com/esky/constellations/aries.html > "Because of the effects of precession on the Earth, though, the First > Point of Aries moves through the sky, and in fact it left the > constellation from which it takes its name in about the year 70 BC, > when it entered the neighbouring constellation of Pisces. > Nonetheless, it retains the name 'First Point of Aries'. Roughly > 23,000 years from now, the Sun will have completed its circuit of the > zodiac, and the First Point will once again lie among the stars from > which it takes its name. " > Xmas is 3.5 days after the solstice, New Year is a week after Xmas, > Easter wanders about because it is tied to the Sunday sabbath, the > Moslem sabbath is a Friday noon prayer, Gawd put down his hod and > trowel and rested on the seventh day; the calendar is an unholy mess > that has been meddled with by priests of all religions, all of whom > refuse to come to a consensus because they all interpret their > written texts differently and what is written is holy in their sight. > > The calendar shifts because the Earth precesses and if that is > inconvenient to Andrew Usher's Thanksgiving on a fourth Thor's (Norse > god of thunder) -day in the ninth month (Nov-ember) then too bad, Usher. > > "Who will rid me of this meddlesome priest?" -- Henry II Whether or not the calendar is inconvenient to Andrew Usher, the precession of the equinoxes is not responsible for the drift of the *date* of Vernal Equinox that led to the Gregorian Reform. The main cause is the difference between a calendar's approximation to the average length of the Tropical Year (365.2500d for Julian calendar) and the actual Tropical Year (365.2422d). The Tropical Year is the mean interval between Vernal Equinoxes when the Sun crosses the equator from S to N. The Gregorian calendar has an average year 365.2425d, a very close approximation that won't go seriously wrong for a few millennia. What precession does, as you point out, is cause the position of the First Point of Aries to move along the Ecliptic, gradually shifting among the background stars. But this has no effect on seasons or calendar; it simply affects which stars and constellations are seen during various seasons. Orion is a winter constellation now, but 12,500 years hence it will be a summer constellation (in the northern hemisphere). -- Mike Dworetsky (Remove pants sp*mbl*ck to reply)
From: Mike Dworetsky on 21 Feb 2010 08:40 Andrew Usher wrote: > On Feb 19, 3:07 pm, Ant�nio Marques <antonio...(a)sapo.pt> wrote: > >>>> The reason I fix Christmas to a Sunday has been my observation that >>>> arranging a family Christmas is substantially more convenient when >>>> it falls on a weekend than in the middle of the week. Given that >>>> Christmas is the most important holiday in the year, should we not >>>> all get at least a 3-day weekend, which we have for lesser >>>> holidays? >> >>> Less than around 30% of the world population cares about Christmas >>> or Easter or think that "Christmas is the most important holiday in >>> the year". >> >> Well, but for those who don't it doesn't really matter one way or >> the other what day Christmas and Easter Sunday are, does it? So what >> relevance do they have for you to bring them along? Or was it just >> the desire to sound clever? > > Right, and I figure that my calendar would be no worse than the > present for those that don't. > > Indeed, I considered this problem purely as a logical one; as I've > stated, I don't consider myself Christian, I adopted the Church > calendar as a base only because it makes the problem more interesting. > > I didn't consider my calendar complete until I worked out my new leap > year rule (Rule #3) - it not only ensures that both Christmas and > Easter are within 7-day periods despite being a constant distance from > each other and having leap day in between, it simultaneously causes > there to be exactly 52 Sundays in every year if you take out Nov. 1 > which is All Saints' day; this immediately allows te to draw up a > permanent list of the Sundays in the year with their traditional > Christian designations, and then follow the perpetual calendar. > > And I moved the start of the week numbering to August from Nov. 1 so > that the academic year and the US football season would be on the > fixed schedule, and I think there can be no objection to that. The > holidays I consider are Christmas and Easter (and of course the Church > festivals fixed to them, but hardly anyone cares anymore), and US > Thanksgiving - but other civil holidays could easily be fixed to the > same if they are now observed on a Monday, say, or otherwise not fixed > to a particular date. > > Andrew Usher There have of course been many "serious" attempts at calendar reform, there were even societies devoted to it that published their own magazines. It all sounds wonderful if you are living in the USA, but how are you going to get other countries with their own agendas (such as real football--what you dismiss as "soccer") to go along with it? It's hard enough now getting different (northern) countries to agree on the dates for putting clocks forward or back for Daylight Savings--a nightmare for airline schedulers. How much worse will it be when different countries have their own calendars? Whatever happened to that good old American slogan, "If it ain't broke, don't fix it."? -- Mike Dworetsky (Remove pants sp*mbl*ck to reply)
From: Mike Dworetsky on 21 Feb 2010 08:49 Andrew Usher wrote: > On Feb 19, 1:38 pm, Ant�nio Marques <antonio...(a)sapo.pt> wrote: > >> Easter is the central feast of Christianity, would be an end in >> itself if nothing else, and of which all the particulars have the >> highest religious significance. (Regardless of whatever pagan >> festivals coincide with it in date or outward meaning.) > > I agree, but how does that mean we must celebrate Easter at the full > moon? (which the Orthodox don't, anyway) > > Andrew Usher Come on, the answer to a question about why a particular religious festival must be celebrated on a day fixed by the phases of the Moon is, "Because". So unless you plan to enforce an order to the Catholic Church to abandon a practice that is central to their rituals and celebrations, you are on a hiding to nothing. Possibly you could have a "civil" calendar and leave the Gregorian calendar for "ritual" use only, the way the Orthodox calendar is used, but the point about the way in which the whole world adopted the Gregorian calendar for civil purposes, even if they were Buddhists or Jews or Shinto or Tao or Atheist, is that it led to standardization and a common agreement about dates for civil and international matters. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply)
From: Mike Barnes on 21 Feb 2010 10:59 Yusuf B Gursey <ybg(a)theworld.com>: >On Feb 19, 11:25�am, Mike Barnes <mikebar...(a)bluebottle.com> wrote: >> But I thought that for most people the whole point of Easter is that >> they get time off work. > >not in the US, at least not in my state. So I now understand. Here in England, Friday and Monday are holidays, and school terms fit around them. That's the problem with Easter. I think it's fair to say that many people here would be happy if they fixed the dates of the public holidays (e.g. second weekend in April) and allowed the holy day to shift as it will. I don't if or why disconnecting them would matter to anyone. -- Mike Barnes Cheshire, England
From: jimp on 21 Feb 2010 12:01
In sci.physics jmfbahciv <jmfbahciv(a)aol> wrote: > Andrew Usher wrote: >> Mike Barnes wrote: >>> Adam Funk <a24061(a)ducksburg.com>: >>> >From man 5 crontab: >>>> When specifying day of week, both day 0 and day 7 will be >>>> considered Sunday. BSD and AT&T seem to disagree about this. >>> But they presumably agree that day one is Monday. >> >> But 0 is the start of computer indexing - at least in real programs. 0 >> = Sunday. >> > Where do you get that idea? > > /BAH From crontab and array indexes. -- Jim Pennino Remove .spam.sux to reply. |