Explain

https://www.merriam-webster.com/words-at-play/centuries-and-how-to-refer-to-them

Just as if you are 17, you are in your 18th year, because it’s your 18th trip around the sun.

Or, 0-99 was the first century.

Exactly

Yes

Thats a valid point

Because the 1st century was from the year 1 to the year 99 2nd century from year 100 to year 199 and so on

Thanks everyone! It really got me started

duh