Rules currently in force

From summer 2015 on, Fort Nelson, BC will stay permanently on Mountain Standard Time.

The United States extended its period of DST, starting in 2007. Canada inevitably came under pressure to follow suit, because of its trade and tourism ties to the U.S. In Canada, each province regulates its own observance of DST. All the provinces and territories that observe DST ended up deciding to follow the same schedule as the U.S. in this regard. Therefore, Daylight Saving Time runs from the second Sunday in March at 02:00 to the first Sunday in November at 02:00.

Note: in Manitoba, until recently, due to the wording of the Official Time Act, DST ended at 03:00 on the day it ended. A new Time Act has been promulgated for the changed dates in 2007. As a result, starting in October 2006, DST in Manitoba ends at 02:00, just as in most other provinces. In 2011, Newfoundland changed the start and end times for DST from 00:01 to 02:00. Now all provinces begin and end DST at 2:00 a.m. local time.

It has been reported that Resolute (Qasuittuq), on Cornwallis Island in Nunavut, didn't change its clocks in winter 2006-2007. The alteration lasted only that one year, and now it observes Central Time with DST in the summer as it did before.

Time zone history

To be done.

Time zone names

Canadian standard CAN/CSA-Z234.4-89 establishes the following official names and abbreviations for Canadian time zones:

Note: Yukon Time is not currently in use. Yukon Territory is on Pacific Time at present.

References:
When does daylight saving time start and end? 
Time zones & daylight saving time 
Canadian Geographic article 
Private page  with links to many official sites
Standard Time Act amendment