Explain how the international data line works?

The International Date Line (IDL) is an imaginary line located at approximately 180 degrees longitude opposite the Prime Meridian. It serves as the boundary where each calendar day officially begins and ends; when crossing the line from west to east, travelers subtract a day, while crossing from east to west adds a day. The IDL is not a straight line and zigzags to accommodate political boundaries and island nations. This adjustment helps maintain a consistent timekeeping system across the globe.