Convert Hour (Sidereal) (h (sidereal)) to Year (Julian) (y (Julian)) instantly.
About these units
Hour (Sidereal) (h (sidereal))
A sidereal hour is 1/24 of a sidereal day, approximately 59 minutes and 50.17 seconds of solar time. Astronomers use sidereal hours to measure right ascension and to coordinate telescope pointing systems. Because stars return to the same apparent position after exactly one sidereal day, sidereal hours offer a stable celestial reference frame. While not used in daily life, sidereal hours are indispensable for precision observation of the universe.
Year (Julian) (y (Julian))
A Julian year is defined as exactly 365.25 days, reflecting the structure of the Julian calendar introduced by Julius Caesar in 45 BCE. This calendar assumed a fixed year length with a leap year every four years. Although revolutionary in its simplicity, the Julian year overestimates the actual tropical year by about 11 minutes, causing the calendar date to drift slowly relative to the seasons—an issue that accumulated to more than 10 days by the 16th century. Astronomers still use the Julian year as a standardized unit for long-term timekeeping, especially when expressing stellar motions, orbital periods, and cosmological timescales. Its simplicity and fixed length make it ideal for scientific definition even though it is obsolete as a civil calendar.