On 1/11/2011 1:13 PM, C. M. Sperberg-McQueen wrote (in part): > > 7 The year zero > > Entry 110 reads in part > > BC has no year zero, In the BC system the year before year 1 is 1 > BC. Thus '-0999' means "1000 BC". > > By "BC" and "the BC system" I think you must mean "the Gregorian > calendar". The absence of a year zero applies not just to the time > before the era, but also after. > > The Gregorian calendar did not create the year numbering system, it adopted an existing system. I don't read Latin, so am unable to state for certain, but I don't believe the defining documents for the Gregorian calendar requires the use of the year numbering system devised by Dionysius Exiguus, together with the system for naming years before AD 1 which was devised by Bede. Gerard Ashton