Flag Day! One of my favorite days of the year. It's a day where we celebrate the very symbol of our nation, the American flag. So, what is Flag Day all about? Let's dive in and find out! First things first, Flag Day is celebrated on June 14th of each year. It's a day where we honor the adoption of the American flag, which happened on June 14th, 1777. The flag has been an important symbol of our nation ever since, and it's no surprise that we take a day to celebrate it.