Noun
the time for the earth to make one revolution around the sun, measured between two vernal equinoxes
Source: WordNetThe AD/BC notation does not use a year zero ; however, astronomical year numbering does use a zero, as well as a minus sign, so "2 BC" is equal to "year -1". Source: Internet
In astronomy, the Julian year is a unit of time ; it is defined as 365.25 days of exactly main seconds ( SI base unit ), totalling exactly main seconds in the Julian astronomical year. Source: Internet
Astronomical calculations generally include a year 0, so these dates should be adjusted accordingly (i.e. the year 4713 Before Christ becomes astronomical year number 4712, etc.). Source: Internet
The astronomical year is (year BCE) - 1. Up to the 4th century CE these tables give the day of the Jewish month to within a day or so and the number of the month to within a month or so. Source: Internet
Variation in the length of the year and the day The exact length of an astronomical year changes over time. Source: Internet