Convert Year (y) to Year (Sidereal) (y (sidereal)) instantly.
About these units
Year (y)
A year is the time it takes Earth to complete one orbit around the Sun, approximately 365.2422 days. This value is not exact, which is why leap years exist. The year is the foundation of calendars, agriculture, climate cycles, financial planning, long-term engineering designs, and historical chronology. Its importance spans science, culture, religion, and economics. The modern Gregorian calendar year is an elegant compromise that aligns civil life with astronomical reality, minimizing drift between the calendar and the seasons. Despite its complexity, it remains the global standard for structuring long-term human activity.
Year (Sidereal) (y (sidereal))
A sidereal year is the time it takes Earth to complete one full orbit relative to distant fixed stars, lasting approximately 365.25636 days. This is the "true" orbital period of Earth in space, unaffected by precession-related shifts of the equinoxes. Sidereal years are used in celestial mechanics, spacecraft navigation, and modeling solar system dynamics. The slight difference between the tropical and sidereal year (about 20 minutes) reveals how Earth's wobbling axis alters how we perceive time, creating two distinct astronomical year definitions.