On what date did the NHL retire Gretzky's number 99 league-wide?

The NHL retired Gretzky’s number 99 league-wide on February 6, 2000.

The honor took place at the 2000 NHL All-Star Game, shortly after Gretzky’s retirement and his induction into the Hockey Hall of Fame. It meant that no NHL team could issue number 99 to another player, making Gretzky the only player whose number has been retired across the entire league.

This was different from individual team retirements. The Edmonton Oilers and Los Angeles Kings later held their own ceremonies for Gretzky’s number, but those celebrations did not create the league-wide ban. The NHL-wide retirement was the major distinction.

A common mix-up is with Gretzky’s final game, played on April 18, 1999, or with the Kings’ 2002 retirement ceremony. Neither date marks the league-wide retirement of number 99.