# The law for people born on leap days **URL:** \ **Category:** Factual Questions\ **Created:** [February 29, 2024, 9:54am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274 "2024-02-29T09:54:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [February 29, 2024, 9:54am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/1 "2024-02-29T09:54:28Z")
Are there legal provisions governing when people born on a leap day, i.e. February 29, complete a year of their life? Suppose a child is born today. When will this person become of full age legally? Logically, it must be either February 28, 2042 or March 1, 2042. Which is it? ---
**Author:** ![Max\_S](https://avatars.discourse-cdn.com/v4/letter/m/46a35a/32.png) [@Max\_S](https://boards.straightdope.com/u/Max_S)\ **Post date:** [February 29, 2024, 10:25am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/2 "2024-02-29T10:25:41Z")
My grandmother was born on a Febuary 29, or at least that’s what she told immigration officials. (In China, everyone celebrates their birthday on lunar new year.) Anyways in the U.S. the deal is, you’re one year older after 11:59pm February 28. Same standard used whether a leap year or not. ~Max ---
**Author:** ![SanVito](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sanvito/32/2805_2.png) [@SanVito](https://boards.straightdope.com/u/SanVito)\ **Post date:** [February 29, 2024, 10:29am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/3 "2024-02-29T10:29:40Z")
I imagine it would be 1 March, as the 28th would mean an incomplete year. It’s my Dad’s birthday today. He’s 96 years / 24 birthdays old. He normally celebrates on the 28th. ---
**Author:** ![SuntanLotion](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suntanlotion/32/16165_2.png) [@SuntanLotion](https://boards.straightdope.com/u/SuntanLotion)\ **Post date:** [February 29, 2024, 10:52am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/4 "2024-02-29T10:52:15Z")
Wow! Tell him we said HB! ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [February 29, 2024, 11:03am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/5 "2024-02-29T11:03:05Z")
This is, of course, a plot point in The Pirates of Penzance. ---
**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:** [February 29, 2024, 11:58am UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/6 "2024-02-29T11:58:23Z")
They start counting their age as another year on the first day of the year (also, they count the time their mother was pregnant with them as a whole year), but they celebrate their birthday on the anniversary of the actual day they were born. For things requiring someone be of a certain age, such as marriage, buying tobacco, or buying booze, the age count is done the same way it’s done in western countries. By the way, the day one completes a year of their life is the day _before_ the anniversary day of their birth. That’s determined by something called using the inclusive date. If you happen to have a US passport, check out the issue date and the expiration date. The expiration date is one day before the tenth anniversary of the issue date. That’s an example of the inclusive date being used. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [February 29, 2024, 12:32pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/7 "2024-02-29T12:32:50Z")
If you’re born on Feburary 29 you have to be sure to read all apprenticeship contracts _very_ carefully. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [February 29, 2024, 12:50pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/8 "2024-02-29T12:50:16Z")
German physicist, art commentator, and irrepressible punster George Christoph Lichtenburg (1742-1799) pointed out, you can determine the birthday of even a person born on Leap Day if you go by astronomical dating: > [@](#): > > I wouldn’t even have touched upon this ridiculous topic if the question When shall a person born on February 29 celebrate his birthday? had not been raised rather seriously in a famous magazine and left unanswered. Here is the answer and the consolation: > To be sure, a man is born on a certain day, at a certain date; but his entry into the world, his first drawing breath, is the work of a single second. At this point in time, the sun stands at a certain point of its ecliptic. Therefore a given individual will be exactly one year old the next time the sun stands again in this same point; and the legal day which contains that instant is the person’s birthday in the true sense, whatever the calendar calls it. This, I think is very clear. Put it in the style of a recipe or a set of instructions, it would run somewhat like this: > 1) Have someone tell you the second, minute, and hour of your birth, or if unknown, assume some definite time: for instance, mid-day. 2) Look up the longitude of the sun for this instant in an astronomical calendar. 3) Look up in the calendar for the year in which you intend to celebrate your birthday, the day when the sun will have exactly the same longitude. This day, whatever it is, is your birthday. > If you proceed in this way, you will notice something which will amaze you: if you had been born on any other day — for instance, May 1 — you would nevertheless, under certain conditions, celebrate your birthday on different days, at times on April 30, at times on May 2. Therefore the man born on February 29 isn’t always the only one who has to celebrate on different days of the month from the one which the usual method assigns him. Often one rejoices jubilantly at the death of the old year when it still has eighteen more hours to languish, and congratulates the new one eighteen hours before it is born. So in this case, as in thousands of other happenings of life, it’s a matter of situation and circumstances. > ~Georg Christoph Lichtenberg (1742–1799), “Consolations For The Unfortunates Born On The 29th Of February,” translated by Franz H. Mautner & Henry Hatfield > **[Leap Birthday Quotes](https://www.quotegarden.com/leap-birthdays-feb-29th.html)** > > Quotations about leap day birthdays on February 29th, from The Quote Garden. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [February 29, 2024, 1:30pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/9 "2024-02-29T13:30:41Z")
> [@Max\_S](#): > > Anyways in the U.S. the deal is, you’re one year older after 11:59pm February 28. Same standard used whether a leap year or not. > [@SanVito](#): > > I imagine it would be 1 March, as the 28th would mean an incomplete year. Yes - the legal “aging” happens when the designated year _ends_ – the next day you are already in the next “age year”, whatever you call the next day. Or to use another illustration, someone who would be age X as of 28 February, and age X+1 as of 1 March, is so whether or not there is something old Julius and Gregory called 29 February shoved in between. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [February 29, 2024, 2:36pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/10 "2024-02-29T14:36:26Z")
Indeed so. Many people believe “age” and “number of times your birthday has occurred” and “number of years old” are all fully interchangeable. They are not. As above, the distinction is explicitly clear in the case of traditional East Asian age calculation (no longer used for legal purposes, now that South Korea stopped last year, but still widely used informally) where everyone’s age increments on the New Year instead of on individual birthdays (which, yes, people do know and use). And likewise, ‘number of years old’ is kind of an odd one since the way we reckon years is not as a specific number of days. So, the way it works and the way it makes most sense to have one’s age increments after the previous age-year ends, rather than when a specific date comes around. > [@Max\_S](#): > > My grandmother was born on a Febuary 29, or at least that’s what she told immigration officials. (In China, everyone celebrates their birthday on lunar new year.) As in Monty’s post above, they do not celebrate their birthday on the new year, but it is when their age increments in the traditional system - for legal purposes, they use the international standard, e.g. when one becomes old enough to legally drink is on one’s birthday, not the new year. They do keep note of their individual birthdays and there are birthday celebrations then, even if traditional ‘age’ is not reckoned to have changed on that date. I suspect your grandmother may have been born within a couple months of the lunar new year, with a strong possibility it was actually on the 29th day of the 2nd month of the traditional calendar (for which every month would have 29-30 days - they add a leap ‘month’ every so often, the last occurring in 2023 and the next in 2025). Since lunar and solar calendars don’t line up, being born on the 29th day of the 2nd month does not mean Feb 29 and the Gregorian date it occurs actually shifts from year to year but it’s as good a date to give to immigration officials as any, since it was and still is extensively used informally in East Asia, especially for earlier generations. That’s essentially what my parents did - they replaced (using an example, not the actual date) 10th day of 3rd month with March 10th to give to immigration officials, since Korea was still using the traditional calendar at that time. Though in recent decades, as above, the Gregorian calendar has replaced it for legal purposes. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [February 29, 2024, 3:18pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/11 "2024-02-29T15:18:41Z")
I’ve been in a bar a few times when someone comes in wanting to be served alcohol, claiming they were now of legal age (after midnight). Many bars choose not to fool around with the “Cinderella Rule” and will not serve someone at 12:01 am on their birthday, although in Pennsylvania, technically it is ok. Each state is different, and each bartender/bar can decline to serve anyone. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 29, 2024, 3:33pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/12 "2024-02-29T15:33:11Z")
I remember reading about a court case. A person was fined for buying alcohol the day before his 21st birthday and the court ruled you were legally of age the day before your birthday. Based on my inability to find a reference to that case ever again, I wonder if it really happened. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [February 29, 2024, 3:52pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/13 "2024-02-29T15:52:51Z")
> [@Saint\_Cad](#): > > A person was fined for buying alcohol the day before his 21st birthday I knew a guy (a friend of my daughter) who the local police hated. He had a dirt bike that he routinely rode on the roads. When the police attempted to pull him over he’d whip them the finger and take off, going through fields, into the woods, etc. If the police went to his home, his dad would feign ignorance. When his 21st birthday was approaching, his friends wanted to take him out to celebrate. His work schedule interfered, so they took him out to celebrate the day before his birthday. The police pulled him over when he was on his way home. He was just over the limit. They threw the book at him; DUI, underage, resisting (he claimed he wasn’t). They also delayed his phone call so that he’d spend the maximum time locked up. It really fucked up his life for a few years, although today he is married with children. ---
**Author:** ![Q.Q.Switcheroo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/q.q.switcheroo/32/5713_2.png) [@Q.Q.Switcheroo](https://boards.straightdope.com/u/Q.Q.Switcheroo)\ **Post date:** [February 29, 2024, 4:05pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/14 "2024-02-29T16:05:51Z")
Australia’s Supreme Court took on this exact issue in 2018: > **[Juvenile or adult? Leap-year suspect causes headache for court](https://amp.abc.net.au/article/10242750)** > > A girl born on February 29, 2000, who allegedly broke the law on February 28 exactly 18 years later causes a conundrum for a Canberra court. Should she be treated as an adult? ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [February 29, 2024, 4:16pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/15 "2024-02-29T16:16:06Z")
> [@JRDelirious](#): > > Yes - the legal “aging” happens when the designated year _ends_ – the next day you are already in the next “age year”, whatever you call the next day. But doesn’t this argument assume that a person was born at 12:01am on their birthday? Someone born on March 2, 2000 at 8pm will complete eighteen years of age on March 1, 2018 at 7:59pm; they haven’t completed the eighteenth year in the morning of March 1, 2018. So arguing that the person becomes of age on March 2, 2000 at 12:01am ensures that the eighteenth year really has been completed without having to deal with intraday times. ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [February 29, 2024, 4:17pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/16 "2024-02-29T16:17:25Z")
(At least I remember that when I turned eighteen, I proudly signed my first legally binding document on my birthday, not the day before.) ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [February 29, 2024, 4:48pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/17 "2024-02-29T16:48:10Z")
> [@Schnitte](#): > > But doesn’t this argument assume that a person was born at 12:01am on their birthday? Someone born on March 2, 2000 at 8pm will complete eighteen years of age on March 1, 2018 at 7:59pm; How does that follow? The time of day is irrelevant either way. As some would have it, the calendar needs to read March 02 for age to increment. But in cases of non-leap years, the calendar would never read Feb 29. The claim is rather than the calendar reaching March 02, it is sufficient that it is the day after March 01. No hour/minute precision needed. Midnight is the only time that matters. Legally, your age increments not when the calendar reads Feb 29 (or March 2) but when it is no longer the previous day, i.e. Feb 28. So it doesn’t matter if there is no Feb 29, the day following Feb 28 is the day your age increments. As I noted above, a lot of people think age, the number of times a date has come about, and the number of years that have passed are all equivalent, but they really aren’t. They’re each reckoned a bit differently but we often conflate them anyway. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [February 29, 2024, 5:14pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/18 "2024-02-29T17:14:55Z")
And yes, for most civil purposes, year terms have always been computed based on days completed by civil date, not an exact sidereal year elapsed, and the date you were born is considered day 1 even if you were born at 23:55. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 29, 2024, 7:39pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/19 "2024-02-29T19:39:42Z")
News stories fairly regularly report the birth of twins in two different years, i.e. one born at 11:55 pm on December 31 and the other at 12:05 am on January 1. They don’t seem to follow up these stories to ask if the separate birth years screw them or the parents up in later life. For legal reasons, date of birth is always counted as from 12:01 am. This is just a convenience since many people don’t know their exact time of birth. The same legal fiction means that every person who has turned 18 is treated the same no matter when in that year they were born. Another legal fiction sets alternate dates for leap year births. The world is awash in discussions whether legal fictions should be applied to voting rights, gun ownership, drinking, driver’s licenses, the draft, and a million other draw-a-line issues. The answer always is that any other approach would be unworkably complicated and unevenly applied. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [February 29, 2024, 9:59pm UTC](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274/20 "2024-02-29T21:59:41Z")
> [@Schnitte](#): > > Someone born on March 2, 2000 at 8pm will complete eighteen years of age on March 1, 2018 at 7:59pm Not so. You will complete your 18th year at 7:59:59 on March 2 and not before. But we generally ignore the time of day. It is recorded in hospital records, I suppose but not on birth certificates. I wonder what countries based on lunar calendars. I think I know what happens in Israel where they use a lunar calendar and add a leap month approximately every third year (actually 7 in every 19 year cycle). The way it was explained to me (@Alessan please correct if I get it wrong) is that in a leap year a second month of Adar (called Adar 2) is added after the standard Adar (now called Adar 1). This has the following consequence. If two friends were born, A on the 29th of Adar 1 and B on the 1st of Adar 2, then although they are only one day apart in age, in any ordinary year, B will celebrate his birthday on the 1st of Adar and A on the 29th. Of course in a leap year A will celebrate his birthday one day before B. But what they do in Moslem countries whose lunar calendars do not add leap months I cannot imagine. [Next page](https://boards.straightdope.com/t/the-law-for-people-born-on-leap-days/998274.md?page=2)