Canada is a vast country which covers a variety of time zones, depending on where you are.
PDT (Pacific Daylight Time) which is GMT-8.00 hrs is observed in the most Western side of Canada, in the Yukon Territory and British Columbia. The city of Vancouver is included in this time zone therefore.
In the territories of Alberta and Northwest, MDT (Moutain Daylight Time) is currently being observed which is GMT-7.00hrs.
Saskatchewan in the heart of Canada observes no daylight saving time and is therefore on Central Standard Time (CST) of GMT-7.00hrs.
Manitoba, the territory in the Mid-East of Canada where Churchill and Winnipeg are located observes CDT (Central Daylight Time) which is GMT-6.00hrs.
Much of Ontario and Quebec fall into the zone which is EDT (Eastern Daylight Time) which is GMT-5.00hrs. The major cities of Toronto, Montreal and Quebec observe this time.
On the Far East coast, GMT-4.00hrs applies in line with Atlantic Daylight Time (ADT). This zone also applies in the areas of New Brunswick and Nova Scotia.
The final time zone that brings the GMT difference to GMT-3.00hrs is that which is observed as Newfoundland Daylight Time (NDT).