A date that means different things to different people. April 20, 1889 Adolph Hitler was born. April 20, 1999 Columbine High School massacre. April 20, 2010 Deepwater Horizon oil rig explodes in the Gulf of Mexico, starting the largest environmental disaster in US history. April 20 is also known as "Weed Day" as pot smokers around the world celebrate 420 (whether 4:20 or 4/20) as a time to indulge. I also mistakenly thought that today was Earth Day. But as I went to find just how many years Earth Day has officially been with us, I found that it is [...]