Though the day is meant as a joyous occasion like Mother's Day or Father's Day, it was inspired by tragedy. New York City woman Claudia Evart was inspired to create the Siblings Day Foundation in the mid-1990s after both of her siblings died at a young age, and she wasn't able to tell them goodbye.
She chose April 10 because it was her sister Lisette's birthday, according to the foundation website. The goal of the foundation is to make the occasion an official national holiday.
"Our mission is to help all brothers and sisters to reconnect," Evart said in a video promoting the holiday. "Cherish, love and respect your brothers and sisters. The deep bond you share is truly a special gift."