An abacus calendar is a kind of calendar that makes use of an abacus to signify the times, months, and years. Abacus calendars have been first developed in China through the Han Dynasty (206 BCE – 220 CE), and so they have been used for hundreds of years to maintain observe of time. In contrast to fashionable calendars, that are based mostly on the photo voltaic yr, abacus calendars are based mostly on the lunisolar yr, which is the time it takes for the moon to orbit the Earth 12 occasions. Subsequently, the size of every month in an abacus calendar can fluctuate between 29 and 30 days.
Abacus calendars are nonetheless used in the present day in some components of the world, notably in East Asia. They’re typically used for spiritual functions, reminiscent of figuring out the dates of festivals and holidays, and so they will also be used for sensible functions, reminiscent of protecting observe of appointments and occasions. Abacus calendars are a invaluable instrument for anybody who’s curious about studying extra about Chinese language tradition and historical past, and so they will also be a enjoyable and academic strategy to study concerning the fundamentals of astronomy.
