Years are ordinal numbers, the kind of number that tells you which place you finished in a race, and as such cannot have zeroes or negatives. You're living in the 2,024th year since the instant that began the Common Era. "0th" and "-1st" are not valid expressions for years for the same reason that you can't place 0th in the Olympics
Ordinals are largely used for counting and when you're counting you kind of do start a zero, most people just don't say it. When you count 1... 2... 3... it would work just as well to start 0... 1... 2... 3... So programmers can rest easy.