Claudia Evart, a woman who lost both her sister and her brother in separate accidents, created the day to honor the special relationships between siblings. It is on April 10 every year.

The term 'sister' originated from the Old Norse word 'systir,' which itself derives from the Proto-Germanic word 'swester.' ...

However, National Siblings Day was founded in the U.S. in 1995 by Claudia Evart, who created the day after losing her brother and sister at a very early age, per National Today.

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.

The Duggars celebrate sibling day. Pic credit: TLC The Duggars are celebrating National Sibling Day with some photos from Justin Duggar and Claire Spivey’s wedding.

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.