Boxing Day is a public holiday observed in many Commonwealth countries (英联邦国家) on 26 December. In many European countries it is also a holiday, called St Stephen's Day or the Second Day of Christmas. Strictly defined as the first weekday after Christmas [1], popular usage [2] has more recently maintained that Boxing Day always falls on the 26th, and that its associated public holiday may fall on a different day.

There is much dispute over the true origins of Boxing Day, but one common story of the holiday's origins is that servants and tradesmen received Christmas gifts from their employers on the first weekday after Christmas, the day after the family celebrations. These were generally called their "Christmas boxes." Another story is that this is the day that priests broke open the collection boxes and distributed the money to the poor.

In Commonwealth countries, any fixed-date holidays falling on Saturday or Sunday are always observed on the next weekday, so if Boxing Day falls on a Saturday then Monday 28 December is a public holiday; while, if Christmas Day is a Saturday then both Monday 27 December and Tuesday 28 December will be public holidays. In the government holiday listings of the United Kingdom for 2004, the bank holiday in lieu of Boxing Day was observed on Monday 27 December, before the holiday in lieu of Christmas Day on Tuesday 28 December.