1990 (MCMXC) was a common year starting on Monday of the Gregorian calendar, the 1990th year of the Common Era (CE) and Anno Domini (AD) designations, the 990th year of the 2nd millennium, the 90th year of the 20th century, and the 1st year of the 1990s decade.

1989 (MCMLXXXIX) was a common year starting on Sunday of the Gregorian calendar, the 1989th year of the Common Era (CE) and Anno Domini (AD) designations, the 989th year of the 2nd millennium, the 89th year of the 20th century, and the 10th and last year of the 1980s decade.