The Earth rotates from West to East, with morning, noon, afternoon, and evening appearing in countries around the world in a cyclical manner. So, where should a new day on Earth begin and where should it end?
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The International Date Line starts from the Arctic, crosses the Bering Strait, the Pacific Ocean, and extends down to the Antarctic (Image: gi.alaska) |
There has been considerable debate over this issue, leading to numerous misunderstandings and complications. For instance, in the 19th century, a small town near Ivancoxevich, Russia, had a postal employee who sent a telegram to the Chicago post office at 7 AM on September 1. However, the reply was recorded as having been received at 9:28 AM on August 31… This left everyone puzzled as to why a telegram sent in September was received in August. Such occurrences were not uncommon at the time.
To avoid confusion regarding dates, the International Meridian Conference held in Washington in 1884 established a International Date Line. This line runs along the 180th meridian in the Pacific Ocean and serves as the boundary between “today” and “tomorrow”. To prevent a single country from having two different dates, this boundary is not a straight line but rather a jagged one. It starts at the North Pole, traverses the Bering Strait, the Pacific Ocean, and extends to the South Pole, ensuring it does not pass through any country. Midnight along this line is indeed 12:00 AM local time. According to regulations, crossing this line results in a change in date. Traveling from West to East requires adding one day, while traveling from East to West requires subtracting one day.
The International Date Line serves as the starting and ending boundary of a day, making the 12th meridian time zone it crosses a unique time zone. In this time zone, time is uniform, but dates are not; they differ by one day. Thus, the Western side is one day ahead of the Eastern side. People living on the Kamchatka Peninsula will celebrate New Year’s Eve first in the world, while those in Alaska will have to wait another day and night to celebrate, even though they are just a stone’s throw away from each other.
