From Longman Dictionary of Contemporary EnglishInternational Date LineˌInternational ˈDate Line noun [singular] SGan imaginary line that goes from the North Pole to the South Pole, to the east of which the date is one day later than it is to the west
Examples from the Corpus
International Date Line• The 113-year-old international date line was drawn arbitrarily and designed to avoid touching land.• Barring a redrawn international date line, which is unlikely, the Chatham Islands it is.