Main Page | See live article | Alphabetical index

Astronomical year numbering

Astronomical year numbering refers to an alternative method of numbering years in relation to the Common Era. In astronomical year numbering, the year 1 BCE becomes 0, the year 2 BCE becomes -1, and in general any given year n BCE becomes -(n-1). Years CE are identical. The system is so named due to its original use by astronomers. It is more convenient to have a year 0 when subtracting years and computing time intervals across the epoch. However, astronomers mostly find it convenient to use Julian days when making computations.