A year is the length of time it takes for the Earth to complete one full orbit around the Sun.

Length of a Year

• Calendar Year (Common Year): 365 days
• Leap Year: 366 days (occurs every 4 years to account for the extra approximately 0.25 days per year)
• Tropical Year (Solar Year): About 365.2422 days - this is the time between one vernal equinox and the next, and it’s the basis for our calendar year.

Summary

• A year is roughly 365.24 days long.
• To keep calendars aligned with the Earth's orbit, we add an extra day every 4 years (leap year).

If you want more details on different types of years (sidereal, anomalistic, etc.) or how leap years work, feel free to ask!