” ...In many countries December 26 commemorates the life of St. Stephen, a Christian deacon in Jerusalem who was known for his service to the poor and his status as the first Christian martyr (he was stoned to death in ad 36).
In the United Kingdom and some Commonwealth countries, the December 26 holiday is commonly known as Boxing Day, which takes its name from the practice of giving small gifts to household servants on that day for their work throughout the year. In Ireland the holiday is sometimes called Wren Day, because in the past a wren would be killed and taken door-to-door by children asking for money in exchange for a wren’s feather, which people believed brought good luck. The tradition of going house-to-house on St. Stephen’s Day survives in many countries, especially in Scandinavia, where the day is observed by visiting friends and going to parties.”
Source.
Nothing remotely related to shopping frenzies.