Some characteristics of the International Date Line include:
1. It marks the boundary between two consecutive calendar days.
2. It is located opposite the Prime Meridian, which is the line of longitude that runs through Greenwich, England.
3. It is not a straight line, but rather zigzags to avoid dividing countries and territories in half.
4. It is not a fixed line, but rather follows the contours of the land and sea.
5. When crossing the International Date Line from west to east, you add a day to the calendar. When crossing from east to west, you subtract a day.
6. The International Date Line passes through the middle of the Pacific Ocean and is mostly located in open water, with a few exceptions where it passes through island nations.
7. The exact location of the International Date Line is subject to international agreement and has been adjusted over time to accommodate changes in political boundaries and other factors.