Christmas Jumper Day is an annual fundraising campaign in the UK organised by charity Save the Children. On Friday 13th December this year, people are encouraged to "make the world better with a sweater" and raise funds for the poor by wearing a Xmas jumper and making a minimum donation of £1.
Those taking part can wear a Christmas jumper they already own, decorate an existing jumper with festive decorations, or even knit their own. Christmas Jumper Day is popular with schools and workplaces.
Save the Children launched their Christmas Jumper Day in 2012 on Friday, 14 December and it has become extremely popular all over the world.