With some exceptions, the clock time between Canada and the United States does not differ within the same time zone. Canada has two additional time zones located east of Maine.
For example, 4 p.m. Eastern Standard/Daylight Time in New York, Boston and Miami is also 4 p.m. in Quebec province, most of Ontario and some of the Nunavut territory. One hour behind is the Central time zone, which includes Chicago, St. Louis and Dallas and shares the same time as Manitoba, western Nunavut and western Ontario. The Mountain and Pacific time zones also are shared with American states. They are, respectively, two and three hours behind Eastern time.
The Atlantic and Newfoundland time zones are wholly Canadian. New Brunswick, Nova Scotia, Labrador and Prince Edward Island are one hour ahead of Eastern time and Newfoundland is 1 1/2 hours ahead.