What would you do with one more summer day? Maybe swim, fish, go to a ballgame, bike, or take a walk with a friend — but something outdoors, right?

Well, on Feb. 29 we get an extra day — of winter — which most of us will spend indoors, wearing heavy clothes, and maybe refilling the car's windshield wiper fluid. Feb. 29 is Leap Day, which some try to disguise as the quadrennial celebration of winter, and for which we can thank Julius Caesar.

Since the Julian calendar bearing his name was invented more than 2,000 years ago, Leap Day has been when the laws of humanity accommodate the laws of nature. Because the earth requires 365 days — plus six hours — to circle the sun each year, we need Leap Day every four years for our human clocks to catch up with the celestial clock.

Without Leap Day, the four seasons of nature would slowly shift on the human calendar, so that in a few hundred years a Minnesota Christmas Day would find us wearing shorts and mowing the lawn.

In fact, this matter is so important that a few years ago there was a global conference in Geneva devoted to the controversial Leap Second — the smaller version of Leap Day. Responsibility for this instant event falls to an outfit called the International Earth Rotation and Reference Systems Service. Really.

Sounds exciting, but there's a much bigger issue at stake. Global summer equality.

Leap Day just isn't the same for everyone.

Folks residing below the equator, in the southern hemisphere, experience Feb. 29 as another summer day. They get to smear aloe on sunburned skin and say stuff like, "It's not the heat, it's the humidity." Here, at 45 degrees latitude north, we pin our summer plans on a groundhog.

After 2,000 years, this doesn't seem fair. Especially when you consider that 90 percent of the Earth's population lives in the northern half. Heck, there are more folks in China alone than below the equator.

It's time we did something about this injustice, but what?

Thankfully, there's a simple solution, lying right in the Mother Goose nursery rhyme, "Thirty days has September, April, June, and November."

Yes, June, that wonderful month of summer's promise, can use another day (July and August already have their allotted 31 days). All we need do is literally turn the world upside-down by moving Leap Day from Feb. 29 to June 31.

Makes you feel warm just thinking about, doesn't it?

To be clear, there will be naysayers — we'll call them "Winterists," or Australians. They will argue that the idea is moot: We'll get 366 days in 2016 no matter what, so putting the extra day in June doesn't matter.

Fine. So when June 31 comes around, they can pull on a parka and stand by the open freezer in the basement.

And there will be consequences. Those born on earlier Leap Days will never celebrate another birthday, and officially will never age. To them we say, "You're welcome."

For the rest of us, pass the sunscreen.

Robert A. Schroeder lives in Minneapolis.