It's Labor Day in the United States. (Also, Labour Day in Canada.)
Per the US Department of Labor, Labor Day "constitutes a yearly national tribute to the contributions workers have made to the strength, prosperity, and well-being of our country." It's been around for more than 100 years, beginning with union celebrations, then state holidays, and eventually a federal holiday.
These days, Labor Day is known more as the unofficial end of summer than for celebration of workers. Growing up, I mainly remember it as the signal that it was time for school to start up again. That's no longer as much the case, as many schools start up in August now, but the long weekend is still a yearly milestone.
As with most holidays, I spend most Labor Day weekends at home, avoiding the extra traffic on the roads and in public places. When I was consulting and doing a lot of traveling, that was especially relaxing - a chance to not drive or fly somewhere. That lifestyle has changed, but spending holidays quietly at home is still my preferred celebration method.
Apparently, it's also National Cheese Pizza Day on September 5th. Probably won't bother going out to get a pizza to celebrate, but I've had enough cheese pizza (as well as with other toppings) in the last year that I feel I've done my part.
So, Happy Labo(u)r Day! Enjoy the remaining summer weather while it lasts.