What is groundhog day based on?

Groundhog Day is based on a folk tradition celebrated in the United States and Canada on February 2nd, where a groundhog is said to predict the weather for the upcoming weeks. According to the tradition, if the groundhog sees its shadow, it will retreat back into its burrow, indicating six more weeks of winter; if it doesn't see its shadow, an early spring is expected. The holiday has roots in ancient European celebrations of Candlemas Day and has evolved into a popular cultural event, particularly in Punxsutawney, Pennsylvania. The concept gained further popularity through the 1993 film "Groundhog Day," which explores themes of time and personal growth.