The demarcation time line is a conditional line that defines a date change at its intersection. Although it is defined only by agreement between people, nevertheless this line has an important property. If you sail on the ship and cross it from east to west, and do it exactly at midnight, then there will be an unusual thing: you jump in a day and instead of getting into tomorrow, you'll get right into the day after tomorrow.
If you swim from west to east, then it will be quite different, but also an unusual thing. If you cross this line exactly at midnight, then instead of getting on the next day, as at any other point on the globe, you will get to the beginning of the same day that just ended. This conditional line, which has such unusual features, runs along the meridian with a longitude of one hundred and eighty degrees.
The term "line of demarcation" is usually used in a geographical sense. However, this expression has other meanings. The term "demarcation line" Korea, for example, uses the meaning of the state border. Once, having entered into an armed conflict, North and South Korea could not come to peace. With the participation of the international community across the country, a demarcation line was conducted, dividing Korea in two. And now the two countries coexist, each of them has the opportunity to live his life, and not be in a continuous and long-term state of debilitating war. This demarcation line was drawn at the thirty-eighth parallel. With its establishment in 1953, peaceful negotiations began between these countries, they continue to this day. This demarcation line is considered to be the last material monument (after the destruction of the Berlin Wall) of the Cold War. It is interesting that under it were discovered more than ten well-equipped tunnels, through which North Korea had the opportunity to transfer troops to the territory of South Korea for military operations. The width of the border zone is four kilometers. In the territory of this state, additional reinforcement was built, very powerful and expensive, which can stop a massive tank attack.
Another well-known demarcation line is located on the island of Cyprus. It has its own name. It sounds like the "Line of Atilla". The division of the island is made between its northern and southern parts. The first of these is the Greek part of the island, the second is Turkish. And it is interesting that part of the demarcation line passes through the old city of Nicosia, dividing the capital into two parts. In the city, a powerful wall is installed along the demarcation line. The decision to build it was made back in 1964, when serious riots and clashes broke out between the Turkish and Greek populations. This site was then called the "green line". In 2008, work was begun to remove the wall. The length of the line is about one hundred and eighty kilometers, and the width varies from a few meters to seven and a half kilometers.