International Date Line Basics Definition, Types, Examples & Uses

International Date Line Basics

Subject: Static GK (General Knowledge)

Book: General Time Knowledge

The International Date Line (IDL) is an imaginary line running roughly along the 180° meridian, demarcating where a new calendar day begins. Crossing the IDL from west to east subtracts one calendar day, while traveling east to west adds a day. This system helps maintain consistent global dates despite Earth’s rotation. Regions may adjust the line’s position to align with political or economic links—Samoa, for instance, famously jumped across the IDL in 2011 to match business days with Australia. Understanding the IDL is crucial for travelers, navigators, and those tracking international deadlines.