[notfed]

I find this decree frustrating. Someone could have just as easily said "the 'first' century starts at 1 BC" to account for this.

[Thorrez]

Then what is the last year of the first century BC? 2 BC? Now there's an off-by-2!

[karatinversion]

Do you also count the first decade of your life from January 1st of the year before you were born?

[Zambyte]

https://en.wikipedia.org/wiki/East_Asian_age_reckoning

[38]

Or better yet just year 0, why not? Do we say the 80s start in 1981?

[rdlw]

The concept of zero was not popularized in 500s Europe, when the system was devised.

[karatinversion]

And also, the system is a direct descendant of regnal numbering, where zero wouldn’t have made sense even if invented (there is no zeroth year of Joe Biden’s term of office).