(an older post of hers, but she wore this yesterday)
National Tartan Day [4/6] is a US observance on April 6 each year. It commemorates the Scottish Declaration of Independence, from which the American Declaration of Independence was modeled on. It also recognizes achievements of Americans of Scottish descent. [source]
So go eat some oatmeal. Or haggis. And drink scotch. Then play a round of golf.