[hn111]

One thing I found out when programming a timeline lately was that year zero doesn’t exist. It just goes from -1 to 1. Which looks very weird if you want to display intervals of e.g. 500 years: -1001, -501, -1, 500, 1000, etc

[zokier]

ISO 8601, one of the most common date notations, does have year zero. It really depends on what specific calendar you use. Gregorian calendar itself only starts at 1582, anything before that is some sort of extension.