Why is a year 365.25 days?

A year is approximately 365.25 days due to the Earth's orbit around the Sun, which takes about 365.24 days. To account for this extra fraction of a day, we include an additional day, or leap day, every four years, resulting in a leap year of 366 days. This adjustment helps keep our calendar in alignment with the Earth's position in its orbit, ensuring that seasons remain consistent over time.