Through which ocean does most of the international date line pass

Pacific Ocean

Explanation:

Meridian 180 °: it is the place where, at least in theory, a date change is made. That is, the countries that are to the right of the 180 ° Meridian will be located in what we will call the "today" and those that are on the left will be located in "tomorrow".

However, although the 180 ° Meridian should coincide with the International Date Change Line, this does not happen, at least not on the entire route from the Arctic to the South Pole. Some countries and territories that are near or above the 180 ° Meridian have chosen to run the International Date Change Line to the right or left of their borders so that their territories are not located on 2 different days at the same time. Let's look at the particularities of these imaginary lines and go first with the 180 ° meridian:

Starting at the North Pole, the 180 ° Meridian is a straight line that crosses the Pacific Ocean and ends at the South Pole (and then becomes the Greenwich Meridian on the other side of the planet). In its route, the 180 ° Meridian only touches land in 4 places that correspond only to 2 countries: Russia and Fiji. To have more clarity about the route, the thing works like this:

The 180 ° Meridian leaves the North Pole located in the Arctic Ocean at coordinates 90 ° 0'N 180 ° 0'E. From there it goes down to meet the Wrangel Island in Russia, then the Chukchi Sea and then re-enters Russia in what is known as the Chukotka Autonomous District at the eastern end of Siberia.