Alexander Belopolsky <belopol...@users.sourceforge.net> added the comment:
On Sun, Oct 17, 2010 at 3:54 PM, Boštjan Mejak <rep...@bugs.python.org> wrote: .. > About the if year == 0 check... Well, read Wikipedia's article > http://en.wikipedia.org/wiki/0_(year) which clearly > states that "Year zero does not exist in the widely used Gregorian calendar > or in its predecessor, the Julian > calendar." So we raise a ValueError if this value is used in the > calendar.isleap() function. > Well, Wikipedia is not the most authoritative source, but if you go the right article there, you will find that """ Mathematically, it is more convenient to include a year zero and represent earlier years as negative, for the specific purpose of facilitating the calculation of the number of years between a negative (BC) year and a positive (AD) year. This is the convention used in astronomical year numbering and in the international standard date system, ISO 8601. In these systems, the year 0 is a leap year.[2] """ Python documentation states that calendar module implements 'the “proleptic Gregorian” calendar in Dershowitz and Reingold’s book “Calendrical Calculations”'. See http://docs.python.org/dev/py3k/library/calendar.html I don't have Dershowitz and Reingold’s book to check, but ISO/FDIS 8601:2000(E) standard contains a note that states: "In the prolaptic [sic] Gregorian calendar the calendar year [0000] is a leap year." In any case, I think there are more important issues with the calendar module than perceived bugs in isleap() function. See for example issue 10087. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue10073> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
