[schipps]

A Christmas box is, in English tradition, a clay box used in artisan shops. Apprentices, masters, visitors, customers, and others would put donations of money into the box, like a piggy bank, and then, after Christmas, the box would be shattered and all the contents shared among the workers of the shop. Thus, masters and customers could donate bonuses to the workers anonymously, and the employees could average their wages. The habit of breaking the Christmas box lent its name to Boxing Day. The term "Christmas box" now refers generally to a gift or pay bonus given to workers.[5] The Oxford English Dictionary attributes it to the Christmas box; the verb box meaning: "To give a Christmas-box (colloq.); hence the term boxing-day."


Well, so Wikipedia says anyway....

regards

Mick