Date of the Columbine massacre

I just wanted to clear up a fact that was disputed in class today. The Columbine massacre was indeed on April 20, 1999, the day after my younger son was born, as I said. The attack probably was originally scheduled for April 19, but the choice of date may or may not have been related to the Waco/OKC anniversary. The Hitler's birthday suggestion for April 20 has also been made, but it is also just a suggestion.