Why do we reference centuries a step ahead of the year? For example 1900s – 20th Century?

Question

Why not 20th Century being 2000- 2999?

In: 0

Answer 1

if 1900-2000 was the 19th century, you would have to call 0-99 (or 1 to 100) the zero-est century. Since we’re actually counting centuries here (‘first’,’second’ ‘third’ etc), ‘zero-est’ makes no sense. The first 100 years where the first century (century means 100 years)

(Your explanatory sub-question would be about the 2nd or 3rd millennium (1000 years), not the 20th century (100 years))