What's the name given to the 180 degrees longitude line (three words)?

The three word name for the imaginary line that (mostly) passes along 180 degrees longitude is the International Date Line.

The International Date Line runs along the opposite side of the Earth from the Prime Meridian, which takes in the center of world timing at the Greenwich Observatory in London.

Starting at the North Pole, the IDL passes along 180 degrees, but deviates from this line of longitude to pass around certain territories and land masses, such as the eastern tip of Russia and the islands of the nation of Kiribati. At times, the IDL can reach 150 degrees longitude, before heading back towards 180 degrees.

The Difference Between Today and Yesterday

Were you to cross the IDL at any point along its path, you would be stepping into a different calendar date. For those heading from east to west, you would gain a day, while those travelling in the opposite direction would find themselves experiencing the same day twice!

Learn more about the International Date Line by watching this film: