The calendar will of course continue to be adjusted in the future. The insertion of a year zero would greatly simplify and modernize counting of the years, and the change of an arbitrary date errantly selected 1200 years ago for an event that happened 800 years previous to that would not be nearly as traumatic to society as was the adoption of the Julian or the Gregorian calendar. In actual fact, people seem to be making such an adjustment even over the objections of the calendar authorities. Whether or not the years B.C. become identified as negative numbers, great numbers of people seem to be inserting a year 0 into the calendar, and intend to celebrate the beginning of the third millennium in the year 2000 and not in the year 2001. The Royal Greenwich Observatory and other official organizations cannot officially condone the year 2000 without an official act of law.
Common people have no such restriction.
The system that is used by people with a more modern approach, which recognizes the year 2,000 as the beginning of the next millennium, should also be recognized to be valid. For more on the nature of time and the evolution of the awareness of time and space throughout the history of the species Homo Sapiens, please visit the website 5dSpace-Time.org.