Our calendar is based on the length of the tropical year rather than the sidereal year.

Question

Quizplus · Accepted Answer

The tropical year is the time it takes for the Sun to return to the same position in the cycle of seasons, and it is approximately 365.24 days long. The sidereal year, on the other hand, is the time it takes for the Earth to complete one orbit around the Sun, and it is approximately 365.26 days long. Because our calendar is designed to match the cycle of seasons, we use the tropical year as the basis for our calendar.

Our Calendar Is Based on the Length of the Tropical