Microsoft released MS-DOS 1.0 to IBM, the operating system that would launch the PC era and make Bill Gates's company a software giant.

MTV launched at 12:01 a.m. with the Buggles' 'Video Killed the Radio Star,' inaugurating an era in which music videos became central to pop culture and celebrity.

Belize became fully independent from Britain, the last mainland Central American colony to break free of European rule.

The United Nations General Assembly designated an annual International Day of Peace, later fixed permanently on September 21.