# Why does February only have 28 days? **URL:** \ **Category:** Factual Questions\ **Created:** [August 17, 2003, 3:22pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780 "2003-08-17T15:22:17Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Beastal](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Beastal](https://boards.straightdope.com/u/Beastal)\ **Post date:** [August 17, 2003, 3:22pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/1 "2003-08-17T15:22:17Z")
All other months get 30 or 31, but February gets a mere 28, 29 in a leap year. Why is this? ---
**Author:** ![Mr.Blue\_Sky](https://avatars.discourse-cdn.com/v4/letter/m/d26b3c/32.png) [@Mr.Blue\_Sky](https://boards.straightdope.com/u/Mr.Blue_Sky)\ **Post date:** [August 17, 2003, 3:30pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/2 "2003-08-17T15:30:17Z")
[Here’s one answer](http://www.naturalistsalmanac.com/0228days.html) ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 17, 2003, 3:35pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/3 "2003-08-17T15:35:36Z")
It goes back to Roman times. Julius Caesar established the calendar we pretty much know today (that included a leap year). For some reason I don’t know he set February to have 29 days and 30 days in a leap year. He also managed to have a month named after him (Julius – July). Octavian Caesar (Julius’ adopted son) came to be Caesar several years after Julius was assassinated. He did such an excellent job that the Senate gave him the name Augustus and gave him a month as well…August (which followed July as Octavian followed Julius). August however only had 30 days in the month and I guess this wasn’t seen as proper (to be less than the 31 days in July) so they snagged another day from February and gave it to August such that February now as 28 days (29 in a leap year). ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 17, 2003, 3:50pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/4 "2003-08-17T15:50:00Z")
I have some data on this, but since it came from Isaac Asimov’s _The Clock We Live On_, which is now out of print (I hear), you might want to verify it elsewhere. This goes back to Roman times. In those days the year began in March (on the Ides, oddly enough) and ended in February. That’s why the “number months” (September-December) are that way. The calendar before Julius Caesar was so badly mangled that Caesar (with the help of astronomer Sosigenes) decided a major reform was needed. He moved the start of the year to January 1 and fixed it so that the months alternated 30 and 31 days, six each, so that the Leap Year had its needed 366 days. The Regular Year (every 4th one under the Julian Calendar reform) had to be reduced by one day. Logically that would be one of the 31-day months. But NO! People didn’t like February all that much since it was in the dead of winter, and at the end of the year, so it got shortened to 29 rather than do the logical thing. But that’s not the end of it. Julius Caesar started the ball rolling by grabbing Quintilis (month #5) as his own and naming it after himself. Along comes Augustus who wants his own month, too, so he swipes Sextilis and makes it August and since he wants his month to be as big as Julius’s he grabs another day from February. (There is some question, Asimov points out, about the real reason behind Augustus’s motives for making the month of August 31 days long.) In any case, that’s one explanation. I bet some Doper has another. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 17, 2003, 3:52pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/5 "2003-08-17T15:52:44Z")
Correction! The Leap Year happens every 4th year in the Julian Calendar, not the Regular Year. My bad! ---
**Author:** ![Monty](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/monty/32/47_2.png) [@Monty](https://boards.straightdope.com/u/Monty)\ **Post date:** [August 17, 2003, 4:02pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/6 "2003-08-17T16:02:03Z")
Zeldar: Almost every 4th year! In a year that ends in 00, if the year’s full number is divisible by 4, then it’s a Leap Year; otherwise, it’s not. ---
**Author:** ![istara](https://avatars.discourse-cdn.com/v4/letter/i/e79b87/32.png) [@istara](https://boards.straightdope.com/u/istara)\ **Post date:** [August 17, 2003, 4:05pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/7 "2003-08-17T16:05:17Z")
**Monty** - sorry, I’ve always had a mental block on this one. Surely every 00 year is divisible by four, because 100 is divisible by four? Or are you supposed to just check with the first two digits (ie 20)? ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 17, 2003, 4:20pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/8 "2003-08-17T16:20:23Z")
> [@](#): > > \*Originally posted by Monty \* > \*\*Zeldar: Almost every 4th year! In a year that ends in 00, if the year’s full number is divisible by 4, then it’s a Leap Year; otherwise, it’s not. \*\* I tried to emphasize that the **Julian** Calendar has every 4th year (no exceptions) as a Leap Year. That is still true. It’s the Gregorian Calendar that “fixed” the calendar so that only the “centesimal years” (ending in 00) divisible by **400** should be Leap Years. The year 1600 was the first of those to be a Leap Year (since the Gregorian reform happened in the 1500’s) and 2000 was the second. The others (1700, 1800, 1900) were Regular Years. The rationale for the Gregorian reform is that the length of the year is not precisely 365.25 days, which was the basis for the Julian Calendar. By the time of the reform from Julian to Gregorian, the year was out of step with the seasons by 10 days, so Pope Gregory XIII decreed that the day following Oct/4/1582 would be called Oct/15/1582. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [August 17, 2003, 4:26pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/9 "2003-08-17T16:26:03Z")
Getting off-topic here but the **Rule for Leap Years** is: Every year that is divisible by 4 (with no remainder) is a Leap Year **Except** any “century year” when divided by 400 and has a remainder will **not** be a Leap Year. So, 1700 1800 and 1900 were **not** Leap Years whereas the year 2000 was but 2100 2200 2300 won’t but 2400 will be, etc I know the wording isn’t the greatest but since this is the Straight Dope Message Board, I was taking into account the fact that, technically, **every** year is divisible by 4 and 400. I know the members here are very precise - (and rightly so). ---
**Author:** ![Monty](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/monty/32/47_2.png) [@Monty](https://boards.straightdope.com/u/Monty)\ **Post date:** [August 17, 2003, 4:26pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/10 "2003-08-17T16:26:30Z")
Whoops! I should’ve said, “divisible by 400.” Guess I had a mental block of my own on the subject! ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [August 17, 2003, 4:29pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/11 "2003-08-17T16:29:11Z")
And while I was typing that, it seems **Zeldar** had posted it already. Good work Zeldar. (Of course I might score anal-retentive points for my divisibilty explanation). ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 17, 2003, 4:42pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/12 "2003-08-17T16:42:42Z")
Another bit of off-topic trivia. One of my bosses had an interesting permanent (perpetual?) calendar that consisted of a stick about a yard long mounted vertically on a disk about 5 inches in diameter. The stick had seven sides/faces and was numbered on each of its faces with a Month/Day from March/1 on the topmost face, in a spiral fashion down to Feb/28 on its bottommost face. There was another 5-inch diameter disk with a seven-sided hole in its center (the size of the stick’s diameter) marked with the days of the week in wedges that corresponded to the faces on the stick. Once a year you would lift off the disk and rotate it one day (if it was a Regular Year) or two days (if it was a Leap Year). Cool toy! It appeared to be quite old, and may even have been centuries old. He said he got it as a gift and didn’t know its origin. But the fact that February (with its odd-day aspect) was at the bottom of the stick, took care of the oddity of that month. I thought that was clever. I pointed out to the boss the bit about how February used to be the last month of the year instead of December, and the boss just grinned as if I was on something. I think he thought I was bluffing or bullshitting him. (It wouldn’t have been the first time – nor was it the last). ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 17, 2003, 4:42pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/13 "2003-08-17T16:42:51Z")
> [@](#): > > \*Originally posted by Zeldar \* > \*\*By the time of the reform from Julian to Gregorian, the year was out of step with the seasons by 10 days, so Pope Gregory XIII decreed that the day following Oct/4/1582 would be called Oct/15/1582. \*\* IIRC this jump in days unsettled quite a few people and they were none too happy about it. Consider the year when this was done…the majority of the populace wasn’t what you would call educated. They felt that they were being robbed of ten days of their lives with this move. ---
**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\ **Post date:** [August 17, 2003, 4:44pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/14 "2003-08-17T16:44:47Z")
> [@](#): > > \*Originally posted by wolf\_meister \* > Getting off-topic here but the **Rule for Leap Years** is: > > Every year that is divisible by 4 (with no remainder) is a Leap Year > **Except** any “century year” when divided by 400 and has a remainder will **not** be a Leap Year. Well, that’s the rule for Leap Years in the Gregorian calendar, which is what most places you’ll encounter use. But the Gregorian Calendar, which is accurate for the next 5,000 years, is not the best calendar there is. The Iranian Calendar is slightly better, accurate for the next 141,000 years. Here’s the rule for [Iranian Calendar](http://scienceworld.wolfram.com/astronomy/IranianCalendar.html) leap years: > [@](#): > > add 38 to the year, multiply the result by 31, and divide by 128. When the fractional part of the result is equal to or greater than 0.31, the year in question is a normal year. On the other hand, if it is less than 0.31, then the year is a leap year, except in the special case that two consecutive fractional parts are less than 0.31, in which case the first is a leap year and the second a normal year. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 17, 2003, 4:52pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/15 "2003-08-17T16:52:08Z")
> [@](#): > > \*Originally posted by istara \* > \*\ ***Monty** - sorry, I’ve always had a mental block on this one. Surely every 00 year is divisible by four, because 100 is divisible by four? > > Or are you supposed to just check with the first two digits (ie 20)? \*\* Your way works, too. Disregard the 00 part and divide the other part by 4. You get the same answer. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [August 17, 2003, 6:34pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/16 "2003-08-17T18:34:29Z")
I read that Julius gave Febrary only 28 days because that month of year was considered unlucky by the Romans and he wanted to get it over as quickly as possible. Any Ancient Rome experts have a take on that? ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [August 17, 2003, 7:04pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/17 "2003-08-17T19:04:23Z")
**Whack-A-Mole** (I know) Way-Off-Topic here - Another reason people got upset with the missing ten days was that landlords charged for a full month’s rent despite the fact the month was lacking those ten days. Also, I believe England did not adopt that calendar until the 18th century and then a 12 day correction was needed. ---
**Author:** ![Beastal](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Beastal](https://boards.straightdope.com/u/Beastal)\ **Post date:** [August 19, 2003, 7:35am UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/18 "2003-08-19T07:35:07Z")
Thanks all. ---
**Author:** ![RedNaxela](https://avatars.discourse-cdn.com/v4/letter/r/ad7895/32.png) [@RedNaxela](https://boards.straightdope.com/u/RedNaxela)\ **Post date:** [August 19, 2003, 1:43pm UTC](https://boards.straightdope.com/t/why-does-february-only-have-28-days/195780/19 "2003-08-19T13:43:09Z")
**wolf\_meister** , I’m not so sure that your statement about rents is correct, since the [British Calendar Act of 1751](http://webexhibits.org/calendars/year-text-British.html) explicitly states: [quote] **VI. Provided also, and it is hereby further declared and enacted, That nothing in this present Act contained shall extend, or be construed to extend, to accelerate or anticipate the Time of Payment of any Rent or Rents, Annuity or Annuities, or Sum or Sums of Money whatsoever… but that[ul][li]all and every such Rent and Rents, Annuity and Annuities, Sum and Sums of Money, and the Interest thereof, shall remain and continue to be due and payable;…[\*]and the said Rents and Annuities, and Grants for any Term of Years, shall commence, cease and determine,[/ul]at and upon the same respective natural Days and Times, as the same should and ought to have been payable or made, or would have happened, in case this Act had not been made…**[/li][/quote] Although I suppose it’s possible that there were people who didn’t know that part of the law and therefore thought they were going to get gouged. (No doubt, too, there were landlords who did their best to make sure their tenants didn’t know!) BTW, the necessary correction at that time was 11 days.