Is 2000 the first year of the 21st century or the last year of the 20th century Give reasons

Is 2000 the first year of the 21st century or the last year of the 20th century Give reasons

The last year is the beginning of the second year

Is 2000 the last year of the 20th century or the first year of the 21st century

This is controversial. According to convention, it should be the last year of the 20th century, but it is generally believed that it is the first year of the 21st century

What's the age of the 21st century?

From the beginning of a century, the first 20 years are called the beginning of the century, 30 years are called the 1930s, 40 years are called the 1940s, 50 years are called the 1950s, and so on, to the end of the last 10 years in 90 years, so now is the beginning of the 21st century