What country actually moved the international date line?

The International Dateline (IDL) zigzags east or west around some territories and island groups.

Two notable deviations of the IDL are due to United States and Russia. The northern-most deviation is east of Wrangel Island and the Chukchi Peninsula, which is the easternmost part of Russian Siberia.Next it deviates west around the US Aleutian Islands to keep it on the same calendar day as the rest of the US.