因无公元零年 ,在计算跨越公元元年的年数时常发生相差一年的问题。这一失误是个尽人皆知的老问题 ,却仍屡见不鲜 ,甚至不乏出现在重大活动上 ,如 1999年在北京举办了纪念孔子诞辰 2 5 5 0周年活动 ,而纪念孔子活动中又明确写着孔出生在公元前 5 5 1年。可是在周年数目的计算上 There is a year-on-year difference in the number of years spanning the first year of the ad because of the zero year of AD. This mistake is a well-known old problem, but it is still not uncommon to see that there have even been many major events such as the commemoration of the 25th anniversary of the birth of Confucius in Beijing in 1999 and the commemoration of Confucius. 5 51 years BC But in the calculation of the number of anniversaries