When McConnell first came up with the idea for Earth Day, he envisioned it as a day for celebrating the wonder of life on Earth. He gave careful thought to selecting the day on which the celebrations should be held. McConnel chose the vernal equinox because on that day, the hours of daylight and nighttime are equal around the world—there is balance. He felt that on such a day, people could join together in harmony to recognize the wonders of our planet.
Earth Day has also inspired other observances such as Earth Week and Earth Hour. Earth Week celebrations in some cities begin on April 16 and culminate on April 22. Earth Hour was first celebrated on March 28, 2009, from 8:30 p.m. to 9:30 p.m. local time.