What is National Flip Flop Day? It is a day to kick off your shoes and socks, and let your feet catch some sunshine in flip flops. There is a deeper meaning to National Flip Flop day though. Founded by Tropical Smoothie Cafe, the company raises funds for their national charity partner, Camp Sunshine, with this national holiday that occurs every year on the third Friday of June. Camp Sunshine is a place where children with life-threatening illnesses and their families can go to make "magical" memories while still receiving the medical and emotional support from professionals.