It's always good to know when the markets are open and when you can take the day off.
The New York Stock Exchange has a list of the days on which the biggest stock market in the world is closed for business.
Bond and other securities markets are somewhat more decentralized, but the Securities Industry and Financial Markets Association (SIFMA) has a list of suggested holidays and half days.
Finally, the Chicago Mercantile Exchange also provides information on when US equity and other futures markets are open and closed during the holiday season.
Here's our guide to US market holidays for 2018 (all times are Eastern Time):
Business Insider/Andy Kiersz