Personalized 100 Days Of School 100 Days Of Cool Toddler Dress. Our 100 Days Of Cool design features a playful and vibrant design that will bring a smile to anyone's face. Whether you're a student, teacher, or parent, this apparel is a fun and stylish way to commemorate the 100th day of school. Your little one will be adorable and comfortable in this 100% combed ringspun cotton 1x1 baby rib dress!