Christmas always on Sunday?

How are you enjoying Christmas and New Years (or Mary, Mother of God) (or Holy Name of Jesus) (or World Day of Peace) falling on Sunday this year??

Astrophysicist Richard Conn Henry and applied economist Steve Hanke propose a calendar where each date always falls on the same day of the week. Christmas could always be celebrated on a Sunday, for instance, and Memorial Day Monday could always be on May 28. Their calendar would make it easy to plan annual activities, from holidays to academic schedules to financial calculations.

The pair says their calendar is different from other alternative calendars proposed in the past because it keeps each week at seven days. “All of the major (other calendars) have involved breaking the seven-day cycle of the week, which is not acceptable to many people because it violates the Fourth Commandment about keeping the Sabbath Day,” Henry says. “Our version never breaks that cycle.”

Read CNN on it here, and read the professors’ article here.

The Second Vatican Council declared in Sacrosanctum Concilium that the Catholic Church “does not oppose efforts designed to introduce a perpetual calendar into civil society. But among the various systems which are being suggested to stabilize a perpetual calendar and to introduce it into civil life, the Church has no objection only in the case of those systems which retain and safeguard a seven-day week with Sunday, without the introduction of any days outside the week, so that the succession of weeks may be left intact, unless there is question of the most serious reasons.”

My first reaction to the proposal? I like.



  1. It’s early, so my math and science skills aren’t functioning, but am I correct in assuming that Easter would still be a “floating” holiday in this calendar? (I.e., it wouldn’t always fall on the same date every year.)

  2. They would drop the quadrennial 366-day leap years entirely in favor of an extra week at the end of December every five or six years. A two week octave of Christmas?

    March 25, the Annunciation always on a Sunday; July 4th on a Wednesday, August 6th the Transfiguration on a Sunday, November 1st on a Tuesday, December 8th on a Wednesday.

    What happens to people with birthdays on January 31st which will not longer exist; maybe everyone in February gets their birthdays moved back so those on February 29th get to celebrate each year on February 30th

    Same problem with birthdays on May 31st which also will no longer exist Maybe everyone in June gets their birthdays moved to one day later. That is OK since there is a June 31st

    Same problem with birthdays on July 31st I guess all August birthdays could be moved to one day later. However the people who now have their birthdays on either August 30th or August 31st would both have to be moved to the same day September 1st, then everyone in September also gets moved to a day later which works out OK since there is a September 31st

    Same problem with similar possible solutions for October 31 which spills over into November and December. December 30th and December 31st would have to celebrate on same day.

    How would this effect the date of Easter? The big issue for churches.

    Changes would require a new Missale Romanum, and a new Roman Missal.

    The natural date for the introduction of these changes is 1 January 2012, because it is a Sunday in both the current Pope Gregory calendar and the simple, new calendar. That does not give us time to change over computer programs to the new, simpler system, of course. But, that does not matter — the change worldwide will take some time, politically, with a natural completion date of 1 January 2017, when Sunday will, once again, fall on January 1st for both the old and the new calendars.

    A new Missal by 1 January 2017!

    1. If March 25 is always a Sunday, then the Annunciation will almost never be observed on that date because it will be bumped by a Sunday of Lent.

      Folks with birthdays that will never fall at weekends will be unhappy because at least under the current system they have the chance to have a day off on their birthday every few years.

      Wedding anniversaries that vanish (e.g. my own on July 31) will also prove a sticky point for some.

      Just a few initial thoughts.

      1. So, a larger segment of the population will have to cope with what folks born on Feb 29 face 3 out of every 4 years? At least, the problem of dropped b’days and anniversary dates will eventually disappear, as those dates will no longer be available!

      2. Well, if you want to make it very Jeopardy-like technical, it would be people born on February 24 in bissextile (leap) years (ante diem sextum Kalendas Martii)…

  3. Easter has always been tied to solar and lunar calendars, so I assume that would continue. Current simplifications, like always using 21 March as the date of the equinox, could be dropped easily and the actual date used. This should keep Easter on the same Sunday in old and new calendars.

    Since this would be adopted by secular agencies, there should be none of the resistance to accepting a Papal proposal that helped keep the Orthodox on the Julian calendar. Though I suppose the Vatican might be upset about using a calendar they did not propose.

    Leap Week might be a problem. Will some Christmas seasons last longer? Or will Epiphany be moved to 37 December, 6 Leap, or whatever we would call that day? Next thing you know they will make Lent last 47 days!

  4. The date of Easter looks to be a complicated matter

    The usual statement, that Easter Day is the first Sunday after the full moon that occurs next after the vernal equinox, is not a precise statement of the actual ecclesiastical rules. The full moon involved is not the astronomical Full Moon but an ecclesiastical moon (determined from tables) that keeps, more or less, in step with the astronomical Moon..

    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.

    Inevitably, then, the date of Easter occasionally differs from a date that depends on the astronomical Full Moon and vernal equinox. In some cases this difference may occur in some parts of the world and not in others because two dates separated by the International Date Line are always simultaneously in progress on the Earth. .

    The added factor provided by the new Calendar is that unlike the old Calendar Sundays always occur on the same date. It looks like Easter this year would occur on the same date in both old and new Calendars because this year they are synchronized. However I suspect the dates for Easter for all non synchronized years may not turn out to be the same in the two calendars. I suspect quite a bit of programming might be required to calculate the results using both Orthodox and Catholic methods for the new Calendar.

    Perhaps an astronomical proposal using astronomical events and a fixed location on earth, e.g. Universal Time, might as Jim suggests help religious leaders to rise above politics.

  5. What I am liking most right now is that Christmas in 2012 will be a Tuesday, because of the leap year. That means with Christmas Eve on Monday instead of Sunday, no finishing Advent in early afternoon and beginning Christmas 4 hours later!!

    While we’re on the topic – when Epiphany is on Jan 7 or 8 (as in 2012), why do we drop that wonderful week between Epiphany and the Baptism of the Lord? Why the big need to rush into Ordinary Time so quickly? Would appreciate some input on this matter, thanks!!

    1. Yes, parish liturgists (such as myself) and musicians are probably very glad that because of the leap year we’ll skip Christmas on Monday. I know I am. And when Christmas is on Tuesday, January 6 is a Sunday, so everybody celebrates Epiphany on the same day.

      Which leads to your question. My assumption is that this is meant so that those who celebrate Epiphany on January 6 and those who celebrate it on the second Sunday after Christmas (i.e., the Sunday that falls between January 2 and 8, inclusive) will be in sync for the Sundays of Ordinary Time. In those places where Epiphany is celebrated on January 6, the Sunday after January 6 is the Feast of the Baptism of the Lord. So this year, for example, such places will celebrate the Baptism of the Lord on Sunday, January 8; they will begin the First Week in Ordinary Time on Monday, January 9; and they will celebrate the Second Sunday in Ordinary Time on Sunday, January 15. But by the calendar in the USA (and other places?), Sunday, January 8, must be Epiphany. If we waited another week for the Baptism, we’d be celebrating that feast while other places were celebrating the Second Sunday in Ordinary Time, and then the following weekend they’d be on the Third Sunday while we’d be on the Second, etc. So when Epiphany is on January 7 or 8, we celebrate the Baptism on the following Monday; when Epiphany is January 6 or earlier, we have the full week between Epiphany and Baptism.

      Like I said, this is my assumption, based on my familiarity with what the Liturgy of the Hours says about the celebrations of the Christmas Season. Corrections or clarifications welcome. I’m glad that my geeky knowledge of the tiny details of the liturgical calendar can (once in a while) be of use to someone. 🙂 By the way, does anyone know if there is a standard name for the Epiphany-on-January-6 calendar and the Epiphany-on-the-second-Sunday-after-Christmas calendar?

      1. But on the years where the Sunday Epiphany is celebrated on January 7 or 8, the Feast of the Baptism is celebrated on the very next day (Monday, Jan 8 or 9); thus the following Sunday is still the 2nd Sunday of OT.

  6. If it ain’t broke, don’t fix it. However, moving Christmas Day to Christmas Eve, meaning having Christmas Day Mass in the morning of Christmas Eve and having Midnight Mass at 12 midnight on the 24th rather than the 25th might work. I could see the following Mass schedule for a December 24th anticipated Christmas:
    Midnight, 7:45 AM; 9:30 AM; 12:10 PM and 5:00 PM and the 5:00 PM could be the Family Mass with pageant. Then no one would have to worry about December 25th Masses and open presents and pig out. All Masses would be finished on the 24th after the 5:00 PM children’s Mass! 🙂

  7. Two potential personal/pastoral quibbles with the proposed static calendar:

    1) “My birthday will always be on a stupid Wednesday.” Or something like that.

    2) Yearly activities that happen to conflict once every few years will then always conflict and require one or more to be shifted around.

  8. As long as the date of Easter is still dependent on the unfolding of the cosmos I’m fine. It kind of keeps us humble and in touch with creation for our most important festival to be dependent on the moon and the rotation of the earth.

  9. If a new calendar is imposed on the Church, let’s see how willing they are to adapt to the change.

  10. extremely OT: I have no problem with moving away from time zones to UTC (Coordinated Universal Time, formerly Greenwich Mean Time except for the BBC which still uses that term). In my almost twenty years as a ham radio operator, I intuitively know when it is 0000 (either 7pm for EST or 8pm for EDT). Remembering that 0000 is a new “world time day” is still tricky for me sometimes. I have computer software that logs radio contacts with the correct date.

    Back on topic: Mainstream Catholics should be aware that Rome’s abandonment of the Gregorian calendar might cause a schism. The Church of Greece had a sizable old calendarist schism after the national synod moved from a purely Julian calendar to a mostly Gregorian calendar. I’d expect some traditionalist groups to break away from the Universal Church should Rome adopt civil calendar reforms similar to the one proposed here. Calendar reform is still worth it both for ecclesiastical and secular society.

  11. I like the idea of a perpetual calendar, but the Comte/Eastman model makes more sense: 13 months of 28 days (4 weeks), with an extra day added at the end (two for leap years). If the extra day is counted ‘outside of time’, each month begins on a Sunday.

    1. Doesn’t work for strict Sabbatarians, so that kind of model simply has no chance of being realized.

  12. There are, just as in Eastman’s calendar, 364 days in each year. But, every five or six years (specifically, in the years 2015, 2020…, which have been chosen mathematically to minimize the new calendar’s drift with respect to the seasons), one extra full week (seven days, so that the Sabbath is unaffected) is inserted, at the end of the year. These extra seven days bring the calendar back into full synchrony with the seasons.

    This statement by the authors suggests that there will be an even larger variation in the date of the Spring equinox, and other such dates, each year, i.e. it will wander from March 21st the traditional date.

    For example, the winter solstice is about Dec 21, which is the 11th day from the end of the year in the current calendar.. However in a year in which a whole week is added after December 31st the 11th day from the end of the year of the new calendar would be December 28th, i.e. it appears the winter solstice might occur after Christmas.

    What I suspect “minimize the new calendar’s drift with respect to the seasons” means is that when seven days are added to a year, it would actually advance the seasonal calendar about three days ahead of what is normal for us now, then allow it to drift back until it is about three days behind the seasons, i.e. the solstices, etc.

    If that assumption is correct is sounds like the Winter Solstice might vary from about Dec 18th on the new calendar to about December 24 on the new calendar, that sometimes be closer to Christmas but not later than Christmas. That is my best guess.

    IF my reasoning is correct, then a similar pattern would occur for the spring equinox between March 18th and March 24 which is why I think predicting its effects upon the Easter date would be complicated.

    1. Though, it should be remembered that the Paschal full moon date is a notional date, not based on the actual astronomical moon phase. In most years, they are the same, but not in all cases.

    2. Jack,

      Going back to an astronomic equinox solves this problem. March 21 currently is used because the equinox falls within 24 hours of that date. That will no longer be true if this calendar is adopted, but will still be true on the old calendar. So using the astronomic equinox will yield similar results. One calendar might have Easter on April 6 while the other has it on April 9, but those dates will describe the same day.

      I have not looked closely.t i think the dates will never be more than a week apart, perhaps always within 4. That practically guarantees the same Sunday described by two different dates. All of this is dependent on adopting a consistent standard reference point like Greenwich is for Universal time.

      The variation between the Julian and Gregorian calendars is greater than any this system would create. Currently the winter solstice falls on Dec 10 Julian and Dec 22 Gregorian (?) but this new calendar detaches itself from planetary regularity in favor of convenience as you show. That is why reverting to astronomy to determine Easter keeps us aligned with the Gregorian while using the simplifications that were designed for the Gregorian would complicate things.

    3. Jim,

      As you may know astronomers use

      Julian dates (abbreviated JD) are simply a continuous count of days and fractions since noon Universal Time on January 1, 4713 BCE (on the Julian calendar). Almost 2.5 million days have transpired since this date. Julian dates are widely used as time variables within astronomical software. Typically, a 64-bit floating point (double precision) variable can represent an epoch expressed as a Julian date to about 1 millisecond precision. Note that the time scale that is the basis for Julian dates is Universal Time, and that 0h UT corresponds to a Julian date fraction of 0.5.

      It is assumed that 7-day weeks have formed an uninterrupted sequence since ancient times. Thus, the day of the week can be obtained from the remainder of the division of the Julian date by 7

      Calendar dates — year, month, and day — are more problematic. Various calendar systems have been in use at different times and places around the world. This application deals with only two: the Gregorian calendar, now used universally for civil purposes, and the Julian calendar, its predecessor in the western world. As used here, the two calendars have identical month names and number of days in each month, and differ only in the rule for leap years

      The astronomical data about the sun and moon needs the Hanke-Henry Permanent Calendar imposed upon it. That should be relatively easy. The beginning of this new Calendar would likely take place in years when weekdays are the same. Then see what happens if we use the astronomical calendar as the basis.

      Most of the variation of the date of Easter caused by the changing relationship between the solar and lunar cycles will remain. If too early or too late dates are produced, it may be possible to adjust the leap year choices slightly.

      The calendar dates should vary about 7-1.75 =5.25 days i.e. 2.6 days around the astronomical dates.

      1. Why, I was just going to say that!

        Not really, but it does provide a convenient way to explain how I think of this. There are 3 calendars here: the Astronomic; Gregorian; and Hanke Henry. Hereinafter Abbreviated AC, GC and HC, with JC for Julian.

        Weekdays match across the board, ie A Sunday in AC is a Sunday in GC is a Sunday in HC. What changes are dates.

        When using AC, Easter is the Sunday after the first full moon after the vernal equinx. This will not change. (though it can be dependent on place, requiring Universal time.)

        GC is abetter approximation of AC than JC is, so much so that it is possible to use March 21 instead of the actual date of the equinox and almost always be correct.

        HC dates will differ from GC by up to 4 days. (I am guessing; 2.6 is the variable difference year to year, but the revised months create differences that even out over the course of the year. HC has 91 day quarters, by GC quarters have 90/1, 91, 92, 92 days) The whole point of changing is so the dates will be different in the new Calendar.

        If HC is adopted. AC dates for Easter will not change. GC dates will not change, and will continue in close correspondence to AC. HC is farther from following the cycles in AC, but its dates will be within 4 of GC. In any event GC and HC will celebrate Easter on the Sunday designated in AC, same day but different date, except on those rare occassions when GC differs from AC.

        On a related, but not relevant, issue, some Eastern Churches use a different rule for determining Easter, the Sunday following following the 14th day after the first new moon following the Spring equinox. There may be other rules out there that give other dates, and the use of the Julian calendar can complicate things even more. It is not entirely like Christmas, which differs only because of the use of different calendars, GC and JC.

        As always, I cannot guarantee everything here is right I hope it helps someone. If not right, I welcome correction.

    4. Of course our assumptions that religious leaders will follow our logic and wisdom may not turn out.

      The Western Church seems not to be concerned that Christmas is 4 days after the solstice, and the Julian Orthodox are not concerned that their Christmas is now on January 7th!.

      Also our assumption of UT may not be shared by religious leaders. I think some Orthodox use Jerusalem time, some Jewish use Jerusalem time or events, and some Muslims use the time or events at Mecca to determine beginnings of some holy days.

  13. I enjoyed two things about the calendar in 2011: The very old Feast of St Stephen was not expelled by the very young Feast of the Holy Family.
    I also enjoyed that the Christmas Octave went from Sunday to Sunday, which makes a lot of sense when it comes to an Octave.

    But the 25th December and the 6th January are such old dates for Christmas, also expressing the vice-versa-influence of Western and Eastern liturgy, that we should not think about any changes of the calendar on that point – for ecumenical reasons. But one must say that the Church doesnt really know what to do with the very very old Feast days of St Stephen, St John, and Sts Innocent, especially when you look at the office: Lauds of the Feast, Vespers of the Octave… And then there is the Feast of Holy Family which expels those old Feasts when they match the Sunday in the Christmas Octave. My person vision is:

    25th – Christmas
    26th – Stephen
    27th – John
    28th – Innocent
    29th – Mary (now on 1st January, since 1960)
    30th – Holy Family (now on the Sunday after Christmas, since late 19th century)
    31st – whatever (or Name of Jesus, now on the 3rd January)
    1st January – Circumcision and Naming (according to the Bibical chronology)

    That would make an Octave of a) very old feasts on these particular days and b) Christmas motifs. On the Sunday of the Octave, the Saint of the Day could be celebrated.

    Hm, well, that would mean a lot of changes in the inner logic of the rubrics. But this is just an idea.

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