Write in brief.
Why doesn’t the IDL pass through land?
The International Date Line was constructed in 1884 to change the date and time according to the global travelling. But unlike the prime meridian, the IDL is not a straight line and does not pass through the land. If it was a straight line passing evenly through the continents, oceans and islands it would have resulted in the same places lying on both the sides of the meridian having different times. Thus the line was constructed in such a way that the parts of the same region were included in the same time zone. Thus the IDL was not a straight line passing through the land.