Grandma Thora Appreciation Day is the first part of the fifteenth episode for Arthur season 2. Grandma Thora Appreciation Day aired on March 9, 1998. It aired with the episode "Fern's Slumber Party".
Arthur and D.W. feel sorry for Grandma Thora because she doesn't have cable TV, can't eat any good snacks, and has to keep her teeth in a glass. So they plan a surprise party for her, but they struggle to make things work and they don't want any help planning the party.