He should just make this into a template and use it for all holidays:

Happy _ Day! ___ be very happy and proud at how well our country is doing today. Best economy in decades, lowest unemployment numbers for Blacks and Hispanics EVER (& women in 18years), rebuilding our Military and so much more. Nice!

Of course, all of what he bragged about in his tweet is subject to interpretation, and there are many things that are not so "Nice!" That could be added to his "Holiday Tweet" Template.

Memorial Day is said to have started after the Civil War. In reality, each war has had people who remembered their loved one's who died and who fought. Now we have a codified holiday in which most folks picnic or enjoy the day and that is what ultimetly those that died were fighting for. That we can enjoy our families, friends, and do the things that bring us joy apart from the everyday workplace. I now longer look to the president to provide inspiration or a saying that I can take to heart, rather I spent the day at a picnic with friends and their families. Those that fought and died would have approved.