We have days to celebrate our mothers and fathers, why not dedicate a day to our siblings? Siblings Day is a holiday dedicated to showing our brothers and sisters just how much we love them. The founders of The Sibling Day Foundation are working to get the holiday recognized nationally in the United States so it can be celebrated with as much enthusiasm as Mother’s and Father’s Day. It has already been proclaimed as a holiday by 49 individual states. It has also been celebrated internationally in many different countries.