Fallacy: BC years can be easily modeled by using negative numbers

[thepaul]

The Gregorian calendar took us from December 31, 1 BC to January 1, 1 AD (there is no year 0). So if you want to know how many years it was from the summer solstice of 5 BC to the summer solstice of 5 AD, you can't just do "5 minus -5 = 10". The difference was really only 9 years.