Hey, Mr Shurtleff, What Day is it Today?

Last Time I checked, July 4th is known as Independence Day here in the United States.

There is a Patriot Day. That day is September 11. There is also a Patriots' Day, Commemorating the start of the American Revolution. That is in April.

So, I was a little confused when Mark Shurtleff sent me an invite to a Patriot Day Tea Party for July 4th: