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Vérificateur d’année bissextile

Vérifiez si une année donnée est bissextile et consultez les règles associées.

Is this year a leap year?

Any year the JavaScript engine supports (about −271,821 to 275,760).

Comment ça marche

  1. The Gregorian rule is applied exactly: a year is a leap year if divisible by 4, except century years (1700, 1800, 1900…), which are not, unless the century is divisible by 400 (1600, 2000, 2400).
  2. The tool states which rule decided the outcome, so the answer is auditable rather than a bare yes/no.
  3. The nearest leap years on both sides are shown, along with the year’s day count (365 vs 366) and whether Feb 29 exists in it.

Bon à savoir

  • The Gregorian calendar averages 365.2425 days per year (three leap days are skipped every 400 years), which keeps the calendar aligned with the seasons.
  • Same-numbered years repeat forever: 2000 is a leap year and so is 2400; 1900 and 2100 are not.
  • For ages and date math around Feb 29 birthdays, the Age Calculator documents its clamping convention (Feb 28 in non-leap years).
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Calculateur d’âge

Déterminez votre âge exact en années, mois, jours et heures depuis votre naissance.

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Différence entre deux dates

Calculez l’intervalle précis entre deux dates en années, mois, semaines et jours.

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Calculateurs de dates

Ajouter ou soustraire des jours

Ajoutez ou retranchez des années, des mois, des semaines et des jours à une date donnée.

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Calculateurs de datesEn vedette

Jours entre deux dates

Comptez le nombre total de jours calendaires séparant deux dates.

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Foire aux questions

What are the leap year rules?
A year is a leap year if divisible by 4, except century years (1700, 1800, 1900), which are not, unless the century is divisible by 400 (1600, 2000, 2400).
Why is 2100 not a leap year?
Century years are skipped unless divisible by 400. 2100 ÷ 400 leaves a remainder, so it is a common year with 28 days in February.
How often is there a February 29?
Roughly once every four years, minus three times per 400 years. The Gregorian calendar averages 365.2425 days per year, keeping it aligned with Earth seasons.