Leap day is not the 29th of February!

In the Straight Dope Classic “When do leap-day babies celebrate their birthdays?”
( http://www.straightdope.com/classics/a960209.html ) Cecil has unexpectedly displayed an embarrasing ignorance as to which day is actually leap day. Leap day - the extra day in leap years - is not the 29th of February, as Cecil mentions. No, leap day is actually the 24th of February, for some reason that escapes my comprehension.

Leap day - i.e. the 24th of February - is a strange day. Tradition has it that on leap day women may ask single men to marry them, and if the man in question refuses, he is liable to a penalty of either 12 gloves of 12 silk stockings to the woman he has refused to marry. I have read some where that this tradition originates in Scotland in 1288 when the queen granted this right to all single women. But I have heard of this tradition in many places. So, guys, beware.

The 24th is the one which loses its status as a saint’s day, with each of the other saints days moving a day later up to the 29th.

I don’t think that there is any official proclamation of February 29th as “Leap Day.” Still, the term “leap day” is used to describe the day added every fourth year to the end of the month of February. It would make sense that, if any day will be called “Leap Day” it would be February 29th.

Indeed, there is an organization devoted to people born that day. They call themselves The Honor Society of Leap Year Day Babies. I’m not sure why they feel they have to add the word “Year” to the designation.

On the rare occasions I have ever heard the term “Leap Day”, it has referred to February 29th. Dictionary.com agrees with me. A somewhat random sampling of hits via google all indicate the same, for example, leapday.net.

Please provide a cite (or a site) that supports your contention of “February 24”. This is a very odd claim which is very counter-intuitive. What, pray tell, is the “official name” of February 24 on non-leap-years?

Someone just gave me something that resembles an explanation of why leap day may be the 24th of February. In the old Roman calendar, predating the Julian Calendar of Julius Ceasar, February was the last month of the year, so that February was the month that had to do the adjustment to match the solar year and the calendar year. Apparently the old Roman calendar had a cycle of four years in which the second year had a February that was only 23 days long and the fourth year a February that was 24 days long (the first and second year had February’s of 28 days, like today). Julius Ceasar changed this in 46 BC to a system similar to the one we have today where February had 28 days except every four years where an extra day was inserted between the 23rd and 24th of February.

As explained by Cecil somewhere in his columns, the Julian Calendar, however more accurate than its predecessors, was actually a bit too long, so that in 1582 Pope Gregory XIII decided to skip leap years in the years divisible by 100, unless also divisible by 400.

At some point in this process January and February were put in the beginning of the year in stead of in the end.

thowan, you’re on the right track. It was the original Julian calendar, introduced in 46 B.C. that repeated what we call Feb. 24. The system in use before Caesar had a normal year of 355 days. At odd intervals, an an intercalary month was inserted to make everything come out right. Even under the new Julian calendar, the Romans had a funny way of counting the days, from our perspective. Days near the end of the month were counted backwards from the first day (kalends) of the next month. In a normal year, the day called a.d. VI kalendas Martii (the sixth day before the kalends of March) was what we call 24 February. (In counting six, they would have included both the first and the 24th). In leap years, the extra day came right after a.d. VI kalendas Martii but was given exactly the same name. To avoid confusion, the second time it was called bis sextus (“second sixth”). The extra day in the calendar is still called bissextile, even though it now occurs on 29 Feb. instead of the sixth day before the kalends of March.

So they had a calendar similar to the Hebrew lunar one with a “leap” month every three years (roughly), huh? That actually makes sense to me as it acknowledges both lunar & solar realities. Why did society change over? And why does the Islamic world keep a lunar calendar alone, without the occasional leap-month?

I must insist that by tradition, leap day is still the 24th of February and not the 29th, as seems to be implied by the wise words of bibliophage and others. My own quick research on the net reveals that the rational option of designating the 29th as leap day is a relatively new custom. The Scottish tradition I speak of in my original posting (the one where single guys can be penalised for refusing a marriage proposal on leap day) is definetely on February 24th and not February 29th. You must take care not to trust modern rationalisations in this respect. It may cost you dearly.

It’d be cool if it were true, thowan, but so far we’ve seen no proof. Let’s see a cite and then we might believe you.


So in a calendar system that we haven’t used in a very long time (not even for religious groups using the current Julian calendar) in a language we don’t speak, the corresponding term for “leap day” applied to a different day.

Call me completely less than impressed with that “logic.”

Well, I’m certainly not as dubious as I was before, thanks to the explanations posted above. And I’m willing to give thowan the benefit of the doubt and accept that in his/her locality, February 24th is traditionally called “leap day”. However, if you want to somewhat rare term to the outside world, I would have to insist the vast majority of modern Gregorian calendar users accept this term to mean February 29th. And, as far as an unofficial term can be considered “correct”, the 29th is correct.

Let me explain.

As bibliophage pointed out, once upon a time the “sixth day before March” was repeated during a leap year, thus leading to the necessity of giving it a special name. This day was equivalent to February 24th. Or actually, a second February 23rd. Now, perhaps there may be very old calendars out there that actually have two February 23ths on it printed on it, thus giving the credence to that second 23rd (actually the “real” 24th) the label of “leap day”.

However, we have long since given up the old Roman habit of (a) referring to days in the fashion of “Nth day before Month X”, and (b) actually repeating a calendar number. Since there are no repeating numbers, the old necessity of specially labeling a “leap day” disappeared. And with it, the general use of the term “leap day” undoubtedly disappeared as well.

Therefore, the closest approximation to the old term “leap day”, if you take it to mean “a day in the calendar that only appears during leap year”, is February 29th.


All of the following is basically from memory, but hopefully more knowledgeable posters can correct any misstatements:

As I understand it, it was because the Roman priests - who were responsible for adding the leap months - had made such a hash of things (by the time of Caesar’s reform the calendar was about two months out of whack, with the spring equinox occurring sometime in May) that Sosigenes, the Alexandrian astronomer who was Caesar’s calendar consultant, recommended just dropping the faux-lunar calendar and switching to a purely solar-based one. (By that time, it wasn’t correctly tracking the phases of the moon anyway; this site, for example, gives the lengths of the 2nd and 4th years of each cycle as 377 and 378, neither of which is divisible into an even number of lunar months.)

Actually, I seem to recall that some Islamic countries, such as Iran, do use a solar calendar. But as for the rest of them, I’ve seen a quotation to the effect that the Qur’an mandates that the year should have twelve months, no more and no less. (I’ve read an old book called Elements of the Jewish and Muhammadan Calendars, which describes how from about 400-600 CE the Arabs actually did have a lunisolar calendar, except that instead of intercalating (as the Jewish calendar does) seven times every 19 years, they intercalated once every three years. Over that 200-year period, then, things got out of whack by several months; their calendar probably would have been reformed eventually, like the Roman calendar, were it not for Muhammad’s opposition to the whole idea of intercalation.)

From Meriam-Webster’s Third New International Dictionary (Unabridged):

From the Oxford English Dictionary, 2nd edition:

The OED also gives the following quotations:

So the usage goes back at least as far as 1712.

The explanation of the issue in Cheney and Jones (A Handbook of Dates, 1945; Cambridge, 2000, p8) agrees with thowan and bib. The remaining confusion also seems covered:

Further to the above: I don’t expect that the Roman Catholic church will have been influenced by Anglican qualms. It’s presumably fairly easy for a Catholic Doper to confirm that their late February saints’ days still shift up by one in leap years. Anyone?

All I’m saying is that in many places - not only in ancient Rome - leap day is traditionally considered as February 24th and not February 29th. If you ask your average Dane on the street, he would agree, as well as your average Scot, as mentioned in my original posting. Several honored members of this user group also point to the custom of shifting names and celebrations one day backward after February 24th in leap years. In one of below provided links there is also an example of a festival for St. Leander on February 27th which is moved to February 28th in leap years. It also seems as if in the European Union February 29th has only officially replaced February 24th as leap day from year 2000 and onwards. Call it overconfident nostalgia from a more than 2.000 year old Roman heritage, but that’s the way the cookie crumbles.

One thing is what is rational, and another thing is tradition. I’m not saying that I prefer one over the other, I’m just raising the issue so that we may all get smarter.

(See http://en.wikipedia.org/wiki/Leap_year or http://www.maztravel.com/maz/explain/calendar.html
or http://www.merlyn.demon.co.uk/leapyear.htm )

I’d be fascinated to know how and when the EU made that change from 24 Feb to 29 Feb, because I’ve searched our database and I can’t find any mention of it…

Unfortunately, not so easy. While every day (except possibly leap day, whenever that is) is the feast day of several saints, most of those feast days aren’t actually observed. And there aren’t any major saints in the last few days of February. There are books listing the feasts of all the canonized saints, but they would presumably just list the “normal” date for the feast (I don’t have such a book handy to check, unfortunately, but don’t recall seeing any notations for moving a feast in leap years).

Okay, it’s a tangent, I know, but I have to smack this one.

From Snopes::

Looking at the Wikipedia entry already linked to, it claims that the Roman Catholic Church has now moved to the English convention and so your recall would be accurate. Which, of course, in turn raises the question of when it switched?