Question

why is international date line broken into many parts and not straight​

Answer 1

Answer:

It is done so as to avoid the confusion of having different dates within the same country.

Answer 2

Answer:

In order to avoid the confusion of having different dates in the same country, the International Date Line bends and goes zig zag at the Bering Strait between Siberia and Alaska, Fiji, Tonga and in some other islands.

hope it helps