Federal Holiday

When are the holidays each year that close the banks and there is no mail delivery?

Here's something interesting that I noticed when I was looking at the Binghamton National Weather Service website.

What is open or closed for MLKJ Day? What is the difference between a National and a Federal holiday? Is there one?

Monday, June 19, 2023 is a holiday in New York State, what is closed, will you be able to go to the bank? Will you get mail delivery?

What is closed or open on the Dr. Martin Luther King national holiday?