Page "Century" Paragraph 1

According to the Gregorian calendar, the 1st century AD / CE started on January 1, 1 and ended on December 31, 100.

The 2nd century started at year 101, the 3rd at 201, etc.

The n-th century started / will start on the year ( 100 × n ) − 99 and ends in 100 × n. A century will only include one year, the centennial year, that starts with the century's number ( e. g. 1900 is the final year in the 19th century ).