--- title: Leap years and 29 February birthdays — a lesson of Mova's school · trees and pragmatics description: «Leap years and 29 February birthdays», a lesson of the world course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: The Earth takes about 365 days and 6 hours to go once round the Sun, but a calendar can only count whole days. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [World](https://md.mova.elamur.ai/free/en/corpora/school/world/) / Leap years and 29 February birthdays # Leap years and 29 February birthdays Lesson 112 of the world course of Mova's primary school: 24 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/world/112-leap-years-and-29-february-birthdays/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/0/) — The Earth takes about 365 days and 6 hours to go once round the Sun, but a calendar can only count whole days. - [1](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/1/) — So every year the calendar falls about 6 hours behind, and after 4 years that makes 4 × 6 = 24 hours, a whole day. - [2](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/2/) — To catch up, February gets an extra day, 29 February, in a leap year of 366 days. - [3](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/3/) — Most years that divide exactly by 4 are leap years: 2024 ÷ 4 = 506 and 2028 ÷ 4 = 507, so both are; 2026 ÷ 4 = 506.5, so it is not. - [4](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/4/) — The extra 6 hours is a little too much: the real year is about 365 days, 5 hours and 49 minutes. - [5](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/5/) — So there is a rule inside the rule: years ending in 00 are leap years only if they also divide by 400. - [6](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/6/) — That is why 1900 was not a leap year, but 2000 was, and 2100 will not be. - [7](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/7/) — People born on 29 February, called leaplings, have their real birthday date only once every 4 years, but they still grow one year older every year. - [9](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/9/) — In ordinary years leaplings choose 28 February or 1 March for the party. - [10](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/10/) — Without leap days the calendar would slowly slide away from the seasons: in 100 years it would be out by about 24 days, and after a few hundred years summer months would land in spring. - [11](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/11/) — The Earth takes about 365 days and 6 hours to go once round the Sun. - [12](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/12/) — A leap year has 366 days instead of 365, with an extra day, 29 February. - [13](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/13/) — 6 hours a year for 4 years makes 24 hours, one whole day, which is why there is a leap year about every 4 years. - [14](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/14/) — Years that divide exactly by 4 are usually leap years: 2024, 2028, 2032 and 2036 are; 2026 is not. - [15](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/15/) — A year ending in 00 is a leap year only if it divides exactly by 400, so 1900 and 2100 are not leap years but 2000 was. - [16](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/16/) — The real year is about 365 days, 5 hours and 49 minutes, a little less than 365 and a quarter days. - [17](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/17/) — A person born on 29 February is called a leapling and gets one year older every year, like everyone else. - [18](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/18/) — In years without 29 February, leaplings usually celebrate on 28 February or 1 March; in the UK a leapling is usually counted as turning a new age on 1 March. - [19](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/19/) — A leapling born in 2016 has real 29 February birthdays in 2020, 2024, 2028 and 2032, and turns 16 on the fourth of them. - [20](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/20/) — People paid the same amount every month get no extra pay for 29 February, so for them it is an unpaid extra working day. - [21](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/21/) — An old custom, said to come from Ireland, says a woman may propose marriage on 29 February; today anyone can propose on any day. - [22](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/22/) — Only one school year in every 4 contains a 29 February: the school year from September 2027 to July 2028 does, and the one from September 2026 to July 2027 does not. - [23](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/23/) — Without leap days the calendar would drift by about 24 days in 100 years (about 25 if you use 6 hours a year), slowly sliding away from the seasons. - [24](https://md.mova.elamur.ai/free/en/corpora/school/world/112-leap-years-and-29-february-birthdays/24/) — Words people use: "leapling" means someone born on 29 February, "craic" means fun (Ireland), "eejit" means a silly person (Ireland) and "highkey" means very openly, the opposite of "lowkey". - ← previous: [Days, weeks and months](https://md.mova.elamur.ai/free/en/corpora/school/world/111-days-weeks-and-months/) - next →: [Seasons, terms and holidays](https://md.mova.elamur.ai/free/en/corpora/school/world/113-seasons-terms-and-holidays/) - ↑ back to [World](https://md.mova.elamur.ai/free/en/corpora/school/world/)