2001 (MMI) was a common year starting on Monday of the Gregorian calendar, the 2001st year of the Common Era (CE) and Anno Domini (AD) designations, the 1st year of the 3rd millennium and the 21st century, and the 2nd year of the 2000s decade.

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.