Astronomical year numbering

The astronomical chronology was supplemented with a Gregorian leap year rule valid valid for all calendar years after the year 1582 and with a Julian leap year rule for all calendar years prior to 1582, and in a way that this era coincides exactly with the Christian era, where the calendar years after the year 4 concerns. Unlike the Christian era, the astronomical chronology corresponds exactly to the day count of the Julian date system. It contains a leap year zero, which are preceded by a minus sign years before. The markings BC or BCE are dropped. The year 1 BC is the year 0, the year 2 BC, the year -1, and the rule states that the year " n" BC to the year (1 -n).

This kind of calendar does not entail that the decades, centuries and millennia begin with the year xyz0 as it pertains to this one ( just to use for purposes of astronomers employed ) intervention only in the part of our era before the moment zero of our era, d. 00:00 h the moment the 1st January 1 So both in the Christian and in the astronomical chronology catch the decades and so on with the year xyz1.