The International Date Line is an imaginary line on the earth’s surface that generally follows the 180° meridian of longitude. This meridian is exactly halfway around (or on the opposite side of) the globe from the Prime Meridian, designated as 0° longitude. An international agreement stated that travelers crossing the line would also experience a change in dates. For instance, travelers who head east on a Saturday will end up on Friday as soon as they cross the line. If the party heads west across the line, it will move from Saturday to Sunday.
Did you know that Tuvalu is located in a time zone that lies on the International Date Line.