Independence Day is always a popular weekend for vacationers and since it falls on a Thursday this year, there are a lot of people who will extend that to a four day weekend. And that’s going to result in the busiest July 4 in three years at the nation’s airports, according to a study by travel app Hopper.

More than 12 million people are expected to fly over the weekend, with 2.3 million flying on the holiday itself. Sunday July 7, though, is expected to be the busiest travel day, with over 3.5 million people heading home.

Atlanta, Los Angeles, Chicago O’Hare and Dallas-Fort Worth will be the pain points, as crowds are expected to be extra dense there. (Atlanta will see over 633,000 passengers.)

As you might expect, that many travelers means a lot of offices will be empty, as well. Over half of the professionals surveyed by Captivate—some 58%—said they were planning to take time off around July 4, with July 5 the overwhelming favorite for extra days.

While traveling around July 4 might be tougher than the past few years, take heart. At least it’s nowhere near as dense as what you’ll experience during the Thanksgiving and Christmas holidays.