November 30, 60AD is supposedly the date that St Andrew was crucified, which is why the patron saint's day falls on this date each year, although it is the following Monday if a Saturday or Sunday.
In 2006 it was made a bank holiday in Scotland, and has traditionally been a day off for students of St Andrews University.
While St Andrew's Day in Scotland and St Patrick's Day in Northern Ireland are bank holidays, St George's Day in England and St David's Day in Wales are not.
The day is usually marked with a celebration of Scottish culture, including dancing, food and music, and both the British Prime Minister and Scotland's First Minister give St Andrew's Day messages.
St Andrew's Day (or in Scottish Gaelic 'Là Naomh Anndrais'), celebrates Scotland's patron saint. It's also an excuse for Scotland to enjoy a bank holiday. But who was St Andrew the Apostle?
St Andrew, according to Christianity's teachings, was one of Jesus Christ's apostles and was born in Bethsaida, in Galilee, now part of Israel. His remains were moved 300 years after his death to Constantinople, now Istanbul, by the Emperor Constantine.
He was revered in Scotland from around 1,000 AD but didn't become its official patron saint of Scotland until the signing of the Declaration of Arbroath in 1320.
Like Jesus, Andrew died a martyr and was crucified in Greece on an X-shaped cross in 60 AD, rather than the 'T' shape cross that Jesus was crucified on. This type of cross is also known as a saltire - the symbol that makes up the Scottish flag.