Karkausvuotta

Karkausvuotta, a Finnish term, translates to "leap year" in English. It refers to a year that contains an extra day, February 29th, making it 366 days long instead of the usual 365. This adjustment is made to synchronize the calendar year with the astronomical year, which is the time it takes for the Earth to orbit the sun.

The Earth's orbital period is approximately 365.2422 days. Without a leap year, the accumulated discrepancy would cause seasons to shift over time. For instance, summer in the Northern Hemisphere would eventually occur in December. The Gregorian calendar, the most widely used civil calendar, implements a system of leap years to correct this drift.

A leap year occurs every four years. However, there are exceptions to this rule. Years divisible by 100 are not leap years, unless they are also divisible by 400. For example, the year 2000 was a leap year because it is divisible by 400, but the year 1900 was not. This refined rule helps maintain accuracy over longer periods. The concept of karkausvuotta is a fundamental aspect of timekeeping, ensuring our calendars remain aligned with celestial movements.