noun
The line of longitude where the date changes by one day when crossed. Used in geography and travel contexts.
飛行機が国際日付変更線を越えると、日付が一日進む。
When the plane crosses the International Date Line, the date advances by one day.
Compound of 国際 (international), 日付 (date), 変更 (change), and 線 (line), directly corresponding to the English term 'International Date Line'.