International Date Line in Class 10 Geography
The International Date Line is an imaginary line that runs from the North Pole to the South Pole, roughly along the 180° meridian. It serves as the boundary between one calendar day and the next.

Significance of the International Date Line
- The International Date Line helps to standardize timekeeping around the world and prevent confusion when traveling across time zones.
- It is crucial for determining the actual date and time when crossing from one side of the line to the other.

Effects of the International Date Line
- When crossing the International Date Line from east to west, a day is gained, while crossing from west to east results in a day being lost.
- This can lead to unusual situations where someone celebrating their birthday on one side of the line may find themselves celebrating it a day earlier or later when crossing to the other side.

Exceptions and deviations
- The International Date Line is not a perfectly straight line and has been adjusted in some places to accommodate political boundaries or to avoid dividing countries.
- Some islands and territories have chosen to be on the same side of the line as their trading partners rather than strictly following the 180° meridian.
In conclusion, the International Date Line plays a crucial role in regulating time and date changes across different parts of the world, ensuring a standardized system of timekeeping despite the Earth's rotation.