In Canada, daylight saving time (DST) is observed in nine of the country's ten provinces and two of its three territories—though with exceptions in parts of several provinces and Nunavut. Under the Canadian Constitution, laws related to timekeeping are a provincial and territorial matter. Most of Saskatchewan, despite geographically being in the Mountain Time Zone, observes year-round Central Standard Time (CST). In 2020, the Yukon Territory abandoned seasonal time change to permanently observe year-round Mountain Standard Time (MST). In the regions of Canada where daylight saving time is used, it begins on the second Sunday of March at 2 a.m. and ends on the first Sunday in November at 2 a.m. As a result, daylight saving time lasts in Canada for a total of 34 weeks (238 days) every year, or about 65 percent of the entire year. History Port Arthur, Ontario (now part of Thunder Bay), was the first municipality in the world to enact daylight saving time, on July 1, 1908. (Germany later became the first country to adopt the time change, on April 30, 1916.) Five Canadian cities, by local ordinance, subsequently used daylight saving time before 1918: Regina, Saskatchewan, on April 23, 1914; Brandon and Winnipeg, Manitoba on April 24, 1916;; Halifax, Nova Scotia on May 1, 1916; Hamilton, Ontario on June 4, 1916. St. John's, Newfoundland (now Newfoundland and Labrador), also used DST before 1918, but the province itself did not become part of Canada until 1949. In practice, since the late 1960s, DST across Canada has been closely or completely synchronized with its observance in the United States to facilitate consistent economic and social interaction. When daylight time became standardized across the US in 1966 when Congress passed the Uniform Time Act, Canada soon followed. DST ended in October until 1986, when the end of the period was changed to November. When the United States extended DST in 1987 to the first Sunday in April, all DST-observing Canadian jurisdictions followed suit. The latest United States change (the Energy Policy Act of 2005), adding parts of March and November to the period during which DST is observed starting in 2007, was adopted by the various provinces and territories on the following dates: Ontario and Manitoba – October 20, 2005 Quebec – December 5, 2005 Prince Edward Island – December 6, 2005 New Brunswick – December 23, 2005 Alberta – February 2, 2006 Northwest Territories –