Christmas Sunday is a name for the Sunday after Christmas. In the United Kingdom, if
Christmas Day falls on a Saturday, December the 26th, is referred to as "Christmas
Sunday", and Boxing Day moves to December the 27th. Since 1999 common practice has
seen December the 26th, remain Boxing Day even when it falls on a Sunday.

In Western Christianity, the first Sunday after Christmas is called the "First Sunday
of Christmas".

In the Eastern Orthodox Church, the "Sunday After the Nativity" is a feast day
commemorating King David, Saint Joseph and James the Brother of the Lord. Special
hymns for these saints are found in the Menaion, which are combined with hymns for
the Feast of the Nativity. If there is no Sunday between December the 25th, and
January the 1st, this feast is moved to December the 26th.