Question map
What will happen if you are flying east across the International Date Line?
Explanation
The International Date Line (IDL) is an imaginary line located approximately at the 180° meridian that separates two consecutive calendar days. When a traveler crosses the IDL moving eastward (from the Eastern Hemisphere toward the Western Hemisphere), they move from a time zone that is ahead of UTC to one that is behind UTC [1]. This transition requires the traveler to subtract one day from the calendar, effectively repeating the same date [2]. For example, crossing eastward on Monday would result in entering Sunday, thereby 'gaining' 24 hours of time to experience that date again [1]. Conversely, traveling westward across the line results in adding a day or 'losing' 24 hours [1]. This convention prevents the accumulation of a full day's error that would otherwise occur during global circumnavigation [1].
Sources
- [1] Exploring Society:India and Beyond. Social Science-Class VI . NCERT(Revised ed 2025) > Chapter 1: Locating Places on the Earth > DON'T MISS OUT > p. 23
- [2] Exploring Society:India and Beyond. Social Science-Class VI . NCERT(Revised ed 2025) > Chapter 1: Locating Places on the Earth > Before we move on ... > p. 24