Multiple choice What is the time adjustment from eastern to western coast of USA? 1 2 3 No time adjustment Reveal answer Fill a bubble to check yourself C Correct answer Explanation 3 A decision was made to adjust the Eastern Time Zone boundary to include The Williams County decision, like all time zone decisions in the USA was. These exchanges then close at 4:00 PM EAST which is 1 : 00 PM on the west coast.