why was earth day planned for april 22?

Earth Day was planned for April 22 primarily to maximize participation from college campuses and avoid conflicts with exams, spring breaks, or major religious holidays. Senator Gaylord Nelson, who proposed the event, chose the week of April 19–25 because it was a time when most students would still be in class and the weather would be reasonably good. He specifically picked Wednesday, April 22, as the date for the first Earth Day in 1970. Additional reasons include that the date did not conflict with major holidays like Easter or Passover and allowed for better scheduling of events. April 22 also came shortly after the anniversary of the birth of famed conservationist John Muir. Interestingly, April 22, 1970, was coincidentally the 100th anniversary of Vladimir Lenin's birth according to the Gregorian calendar, but this was not the reason for the date's selection despite some conspiracy theories. The main focus was on practicality and maximizing impact through student and public participation in environmental awareness teach-ins and events.