Dates: BC dates

Encoding Instructions (new P5 version)

The WWP encodes the when of date for BC dates in the manner of the astronomers. Year 0 is the year preceding year 1 (a.k.a. 1 B.C.). Year -1 is the year preceding year 0 (a.k.a. 2 B.C.). Generally, year -n is the year which began n+1 years before the beginning of year 1 (so year -n = year n+1 B.C.). With the use of this astronomical system of year-numbering there are no limits to the dates which can be expressed in this date format, as long as we are consistent about using 4 digits for the year. Thus the Julian calendar was adopted in date calendar="Gregorian" when="-0045"46 B.C./date. (From “The ISO Date Format” by Peter Meyer (http://barroom.visionsystems.com/serendipity/date/formats.html).)