Question

The International Date Line is located

• A. One the Equator
• B. Along 0 degree Longitude
• C. Along 180 degree Longitude
• D. At Greenwich in UK

Answer 1

The Correct Option is C

Step 1: Understand the concept
The International Date Line (IDL) is an imaginary line on the Earth's surface that marks the place where each new calendar day officially begins. It serves as the “line of demarcation” between two consecutive calendar dates. Crossing this line from east to west means moving into the next day, while crossing from west to east means moving back a day.

Step 2: Location of the IDL
The International Date Line is generally located along the 180° longitude, directly opposite the Prime Meridian (0° longitude). However, it is not a perfectly straight line—it zigzags around certain territories and islands in the Pacific Ocean to avoid splitting countries into two different calendar dates. For example, it bends eastward around Siberia and westward around island groups like Fiji and Samoa.

Step 3: Why along 180° longitude
180° longitude was chosen because it is the midpoint of the globe opposite the Prime Meridian in Greenwich. This makes it the natural place to mark the change of one calendar day to the next. Despite small deviations, its central reference is always 180° longitude.

Step 4: Final justification
Therefore, the International Date Line is described as being "along 180° longitude," even though minor adjustments are made to accommodate political and geographical boundaries.

Final Answer: The correct option is (C) Along 180 degree Longitude.