Fondation de la Haute Horlogerie

Glossary

Century leap year

Introduced with the reform of the Gregorian calendar in 1582 to take into account the time taken for the Earth to make one complete revolution of the Sun, i.e. 365.2422 days. A century year is a leap year every 400 years, i.e. for a century year to be a leap year, it must be divisible by 400.

• french: Année séculaire bissextile
• japanese: 世紀閏年／セイキウルウドシ
• chinese: 世纪闰年