Today is BOXING DAY or St. Stephen's Day in Great Britain. It's also an important day in Ireland, Catalonia... Here's some information about it from the Wikipedia.
Boxing Day is traditionally the day following Christmas Day, when servants and tradesmen would receive gifts from their superiors.
The exact etymology of the term "boxing" is unclear. There are several competing theories, none of which is definitive. The European tradition, which has long included giving money and other gifts to those who were needy and in service positions, has been dated to the Middle Ages, but the exact origin is unknown. It may come from a custom in the late Roman/early Christian era, wherein metal boxes placed outside churches were used to collect special offerings tied to the Feast of Saint Stephen] which in the Western Church falls on the same day as Boxing Day.
In Britain, it was a custom for tradesmen to collect "Christmas boxes" of money or presents on the first weekday after Christmas as thanks for good service throughout the year. This custom is linked to an older English tradition: Since they would have to wait on their masters on Christmas Day, the servants of the wealthy were allowed the next day to visit their families. The employers would give each servant a box to take home containing gifts and bonuses, and sometimes leftover food.
St. Stephen's Day, or the Feast of St. Stephen, is a Christian saint's day celebrated on 26 December in the Western Church and 27 December in the Eastern Church. Many Eastern Orthodox churches adhere to the Julian calendar and mark St. Stephen's Day on 27 December according to that calendar, which places it on 9 January of the Julian calendar used in secular contexts. It commemorates St. Stephen, the first Christian martyr. It is an official public holiday in Austria, Balearic Islands, Catalonia, Croatia, Czech Republic, Germany, Ireland, Italy, Luxembourg, Macedonia, Montenegro, Norway, Denmark, Estonia, Sweden, Finland, Romania, Serbia, Slovakia and Poland.