What is National Tartan Day? Tartan Day is celebration of Scottish heritage and the cultural contributions of Scottish and Scottish-diaspora figures of history. It is held on April 6th to commemorate the day that the Declaration of Arbroath (or the Scottish Declaration of Independence) was signed in 1320. The name refers to tartan, a patterned wool cloth often associated with Scottish clans. Despite its name, it was created in Canada in the mid-1980s. It wouldn’t become a holiday in Scotland until 2004. It has also been celebrated throughout the United States since 1998.