Crossing the IDL

The most crossed dividing line in the world is the International Date Line (IDL). The IDL is an imaginary line that roughly follows the 180-degree longitude line in the Pacific Ocean. It serves as the boundary between two consecutive calendar days. When you cross the IDL from west to east, you add a day to the calendar, and when you cross from east to west, you subtract a day.

The reason the IDL is considered the most crossed dividing line is that it is crossed every time someone travels between certain points in the Pacific Ocean. For example, when flying from Japan to the United States, you typically cross the IDL. This means that passengers may experience a “time travel” effect, where they arrive at their destination before they left, in terms of local time.

It’s important to note that the IDL does not follow a perfectly straight line and has been adjusted in a few places to accommodate different countries’ preferences and economic considerations. Nonetheless, it remains the most widely recognized and crossed dividing line in the world.