Groundhog Day is a popular tradition celebrated in Canada and the United States on 2 February. It derives from the Pennsylvania Dutch superstition that if a groundhog emerging from its burrow on this day sees its shadow due to clear weather, it will retreat to its den and winter will persist for six more weeks, and if it does not see its shadow because of cloudiness, spring will arrive early. While the tradition remains popular in modern times, studies have found no consistent correlation between a groundhog seeing its shadow or not and the subsequent arrival time of spring-like weather.

1993’s “Groundhog Day” capitalized on the holiday and now time loops are forever associated the quasi scientific phenom Punxsutawney Phil.