I should know better but I got into an Internet debate about when the millenium changed (1999 -> 2000 vs 2000 -> 2001 (obviously)). It all started when I made a

I should know better but I got into an Internet debate about when the millenium changed (1999 -> 2000 vs 2000 -> 2001 (obviously)). It all started when I made a joke about the decade not ending yet.