quarantine 'em

"The 20th century ran from 1901 to 2000 inclusive" and other arguments for 0-indexing

Weirdly, extending the Common Era backwards makes more sense. 0th century: -99 to 0 CE -1st century: -199 to -100 CE -Nth century: -NXX CE

The alternative would be to declare "Century N" as the years 100*N to 100*N+99 inclusive. 2000 to 2099 is Century 20. Buuuuut—

—that would lead to the exact same problem in reverse for ancient years. Century -1: -100, -99, ..., -1 CE Century -2: -200, -199, ..., -101

What I'm saying is that we need a year negative zero, which would immediately precede year zero

Century 20: 2000 to 2099 CE Century 1: 100 to 199 CE Century 0: 0 to 99 CE Century -0: -99 to -0 CE Century -1: -199 to -100 CE etc.

All of those annoying off-by-one errors introduced by subtracting BCE years from CE years? They are now off-by-two errors. You're welcome