We could get snow here in Washington on Sunday. Little or no accumulation, they say, but still, snow. (Calla Kessler/The Washington Post)

Snow, or at least some flakes, may fall Sunday in the Washington area. Or maybe not.

But one thing seems less uncertain: Sunday will see Washington’s earliest sunset.

It’s true that the shortest day of the year, the winter solstice, falls Dec. 21. It is also true that the period between sunrise and sunset will continue to shorten until then.

Yet the time of sunset will be a little later on Monday than on Sunday, according to at least one website, timeanddate.com. By the site’s calculations, sunset will be at 4:45 p.m. Sunday, and 4:46 p.m. Monday. (Other sites provide times that differ by a minute or so, but the movement is typically toward later sunsets, even before the solstice.)

This trend toward later sunsets while daylight diminishes comes at a cost. Time gained in the evening is lost in the morning. It is a consequence of the workings of the laws of astronomy, geometry and celestial mechanics and the shape of Earth’s orbit.

Its practical meaning is that while timeanddate.com says Sunday’s sunrise is to be at 7:14 a.m., it says sunrise Monday will be at 7:15 a.m., one minute later.

It isn’t clear if both sunrise and sunset will be visible Sunday. The National Weather Service predicted a 50 percent chance of snow in Washington.