This question was asked on a family WhatsApp group. I will quote it verbatim: “I want (to) know what people mean by we’re in the 21st century. How does it count?”
When I read it I didn’t take it seriously. I expected other people to have it addressed while I just read comments. But when many answers drew us away from what should be correct was when I became interested.
Immediately I consulted google, searched my memory for my Latin and Philosophy, and what you now read is the result.
Thanks to NK who raised the question.
Ans: There were dates counted from billion years down to one (1) at the birth of Christ (Just assume you are a Christian.)
It is known today as BC – Before Christ. (eg. 563BC, 562BC, 561BC, 560BC, 559BC, 558BC, 557BC etc…down to 5BC, 4BC, 3BC, 2BC, end 1BC. It was actually being counted from billions of years down to 1 (One)).
When it ended the world started counting from 000 up.
So 000AD marks the 1st century.
And 001 means we have started counting within the first century. That is the first year of the first century.
AD means Anno Domino = in the year of the Lord. It was estimated that Christ was born in year 1 of the first century.
First-century ended with 099.
Another century started immediately with 100, and that was the 2nd century.
What starts a century is Zeros behind not one (1). One means we have started counting within a century.
Just as 001 meant we have started counting within the first century.
That was why the second century started with 100, and 101 meant the first year of the second century.
So 1900 was the 20th century, which ended in 1999.
And 2000 marked the 21st century.
2001 meant we have started counting within the 21st century, the first year of the 21st century. It will end in 2099.
The year 2100 will mark the 22nd century. And 2101 means the first year of the 22nd century.
Sure you got it?