Also, Sonja, while Katy gave a good list of holidays, they are not all federal holidays where people have the day off work. The holidays that I made green are the ones where government offices and banks and post offices are closed.
Good point, Chuck! Yes, almost all of the above days have some form of traditional celebration -- cards, candy and fancy dinners on Valentine's Day, wearing green and celebrating Irish culture on St. Patrick's, costumes and trick-or-treating on Halloween, etc. But not all are national holidays.
Chuck would be familiar with national holidays, of course, because banks are closed. Newspaper reporters have to work, or at least a few on any given holiday. Usually, people volunteer to work on holidays, either to be cooperative or because on holidays we'd get eight hours pay for five-hour shifts.