Second this for the US. Nothing major as a nation, but various small things in different areas or cities.
I know Hawaii does a Lei Day- “May day is Lei Day in Hawaii”. Not a full on holiday, but there’s usually festivities of various levels around the islands.
We rewatched this movie last fall sometime and (obviously) immediately knew who that was…we were surprised because we didnt know he was in it. Basically this just dates how long it had been since we last saw the movie……