Recurrence pattern: every year on December 4.

National Sock Day is celebrated on December 4th to appreciate socks as both functional and fashionable accessories. Founded by the clothing company Pair of Thieves, the day encourages people to enjoy wearing socks while promoting goodwill and charitable actions. Common customs include purchasing new socks, donating pairs to those in need, and hosting sock-themed parties where guests wear their most colorful or mismatched socks. The event also features activities like sock puppet crafting and watching movies that highlight socks, such as "The Wizard of Oz" and "Clueless." National Sock Day serves as a reminder of the importance of socks in daily life and their role in providing comfort and warmth.