What is the International Date Line?

The International Date Line is correctly identified as an arbitrary line where the date changes, located halfway around the world from the prime meridian. This line runs approximately along the 180th meridian and serves a critical function in coordinating time and date across the globe. When a traveler crosses the International Date Line from west to east, they subtract a day, whereas crossing from east to west adds a day.

This mechanism helps maintain a standardized system of timekeeping and ensures that the world remains aligned in terms of date and time. The International Date Line does not change the hour by one hour, which distinguishes it from time zone boundaries. It also does not indicate the equator, as that refers to a latitude line around the earth. Furthermore, while some countries may have boundaries near the International Date Line, it is not a boundary line between two countries in the traditional sense of political boundaries. The importance of the International Date Line lies in its role in global timekeeping rather than geopolitical divisions.