Answer: The International Date Line is an imaginary line that runs roughly north-south through the Pacific Ocean. It is about 180 degrees east of the Prime Meridian, which runs through Greenwich, England. The International Date Line marks the boundary between one calendar day and the next. When you cross the International Date Line from east to west, you gain a day. When you cross the line from west to east, you lose a day.
So the answer is West.
