In these United States summer is unofficially the sunny, sweltering weeks between Memorial Day and Labor Day. Yes, astronomically speaking, it’s June 21 to September 23. We’re choosing to ignore that here in favor of the cultural definition, because come on, early June feels way more like summer than mid-September.

And this year, we get one extra week. Memorial Day (which is always the last Monday in May) is falling on its earliest possible date, and Labor Day (the first Monday in September) on its last possible date. That means summer stretches an endless 15 weeks instead of the usual 14. The last time this happened was 2009, and the next time will be 2020–see the handy chart below.

So get out there and enjoy it.

Length Of Cultural Summer

Each dot here represents a day, starting with May 1 each year. The days that fall between Memorial Day and Labor Day are in yellow, rather than green. In some years, highlighted in gray, the two milestones capture an extra seven days. And 2015 is one of those magical years.