Exactly. What we call "new" is the 0th year. It's the same when you start counting seconds. You say "ok counting starts now", then wait a second and say "one",

Exactly. What we call "new" is the 0th year. It's the same when you start counting seconds. You say "ok counting starts now", then wait a second and say "one", then wait and say "two". Before you say "one", you don't say zero, but it's implied by you waiting a second after you or someone says "go". That's still 0-indexed.