This paper attempted to suggest that the year 476 as the year of the Western Roman Empire disintegration can be explained as having a precise astronomical meaning, the calculation of which was a normal practice for astronomers in Late Antiquity. By using the remarks of I. Newton and the calculations of L. Euler as well as the Book of Daniel, and the information from Sozomenos and St. Augustine, the author suggests that the astronomers of the 5th century sensed the approach of the year when the Julian calendar, the Easter calendar and the astronomical calendar of tropical year would coincide. The paper’s unique contribution is in showing that the year 476 is the time of the calendars synchronization, if the astronomers used the Hypparchus’ correction of one day in 144 years.
