Big Diomede and Little Diomede are neighbors in the ocean, but a special line called the International Date Line sits between them. Walking from one to the other is like traveling through time!
Imagine standing on a beach and looking at an island just 3.8 kilometers away. You could practically row a boat there in minutes. But if you did, you would arrive 21 hours in the future! This is the strange reality of the Diomede Islands.
These two islands sit right in the middle of the Bering Strait, between Alaska (USA) and Siberia (Russia).
Because the International Date Line runs exactly between them, they are in two different calendar days despite being so close.
In the winter, an ice bridge sometimes forms between the islands. Technically, you could walk from the USA to Russia in about 20 minutes. However, it is one of the only places on Earth where a short walk can change the date on your watch by nearly a full day.
The Diomede Islands are a geographical glitch. They prove that "time" is just a human invention - even if you can see "tomorrow" from your front porch, it's still just a 20-minute walk away!