Prime Meridian And Antimeridian May 2026

But why Greenwich? In the late 1800s, sea travel was booming, but navigation was chaos. Every country used its own "prime meridian" (Paris, Berlin, Washington D.C.—everyone wanted to be the center). Finally, in 1884, 25 nations met in Washington D.C. and voted: Greenwich won. Mostly because the U.S. had already adopted it for its own rail networks, and 72% of the world’s shipping already used it. At the Greenwich observatory, you can literally stand with one foot in the Eastern Hemisphere and one foot in the Western Hemisphere. It is one of the most photographed feet-in-two-places spots on Earth. There is a giant steel line embedded in the courtyard, and a green laser shoots northward into the London sky every night. The Antimeridian: The Land That Time Forgot Now, spin the globe exactly 180 degrees away from Greenwich. You have arrived at the Antimeridian (180° longitude).

Because of how time zones work, the people living just east of the Prime Meridian are "behind" Greenwich time, while those just west are "ahead." But at the Antimeridian, that difference adds up to exactly 12 hours. That means: prime meridian and antimeridian

While the Prime Meridian is a celebration of order, the Antimeridian is a celebration of chaos. It runs mostly through the middle of the Pacific Ocean—but it takes a few dramatic detours. But why Greenwich