Question

Why is the IDL zigzag? 

OR 

Give reason: 

The International Date Line is not straight.

Answer 1

A. Shape of the IDL:

• The IDL is supposed to be straight but it is not.
• At quite a few places, it is zigzag.
• When drawn straight, this longitude passes through many islands of the Pacific Ocean.
• Hence, when the line passed through such islands, the locations there had two days and dates.
• This created a disorder for these islands.
• Hence the IDL was drawn only from the water bodies.
• Thus the IDL does not pass from any land forms.
• To draw it from water bodies, it had to be made zigzag.
• Thus, the shape of the IDL is zigzag.