2000 (MM) was a century leap year starting on Saturday of the Gregorian calendar, the 2000th year of the Common Era (CE) and Anno Domini (AD) designations, the 1000th and last year of the 2nd millennium, the 100th and last year of the 20th century, and the 1st year of the 2000s decade.

1999 (MCMXCIX) was a common year starting on Friday of the Gregorian calendar, the 1999th year of the Common Era (CE) and Anno Domini (AD) designations, the 999th year of the 2nd millennium, the 99th year of the 20th century, and the 10th and last year of the 1990s decade.