What is Spirit Dress Day? Once a month, usually the last Friday of the month, St. Pius X Catholic School celebrates by having a Spirit Dress Day. Students and staff are allowed to wear a SPX spirit shirt and blue jeans. If the weather is too warm for jeans, students will wear their uniform bottoms with their Spirit shirt. Students will wear any color tennis shoes (or their school shoes) on Spirit Dress Days. If the weather is cold, students will wear an SPX jacket or sweater.