Sandford Fleming and standard time
Before the 1880s, Canadian towns kept their own local solar time, just as towns did elsewhere. Sandford Fleming, a Scottish-born engineer who worked on Canada’s railways, became one of the best-known advocates of a worldwide system of standard time. In papers published from 1879, he proposed dividing the world into 24 time zones, each one hour apart, all linked to a single prime meridian.
His ideas fed into the debates that followed. On 18 November 1883, the railways of Canada and the United States adopted standard time zones, and in 1884 the International Meridian Conference in Washington, D.C., chose Greenwich as the prime meridian.
Canada’s six zones
As settlement and railways spread west, Canada’s zones settled into the pattern used today:
| Zone | Standard time | Daylight time |
|---|---|---|
| Newfoundland | UTC−3:30 | UTC−2:30 |
| Atlantic | UTC−4 | UTC−3 |
| Eastern | UTC−5 | UTC−4 |
| Central | UTC−6 | UTC−5 |
| Mountain | UTC−7 | UTC−6 |
| Pacific | UTC−8 | UTC−7 |
Newfoundland’s half-hour offset reflects its position far to the east of the Atlantic zone’s central meridian. Newfoundland joined Canada in 1949 and kept its own time.
Who controls time in Canada
Unlike in the United States, where time zones are set by federal law, time in Canada is mostly a matter for the provinces and territories. Each one decides its zone and whether to use daylight saving time. Some cities and regions have also made their own choices, which is why a few communities keep a different time from the rest of their province.
Early daylight saving time
Canada has a claim to one of the earliest uses of daylight saving time. Port Arthur, Ontario, now part of Thunder Bay, moved its clocks forward in the summer of 1908, years before any national government adopted the idea.
Canada, like the United States, used daylight saving time across the country during both world wars. Between and after the wars, DST was left to provinces and municipalities, and practices varied widely.
Saskatchewan’s choice
Saskatchewan is the best-known exception to clock changes. Its Time Act of 1966 settled most of the province on Central Standard Time all year. Geographically, much of Saskatchewan lies in the Mountain zone, so year-round Central Standard Time works out to Mountain Daylight Time kept permanently. Some border communities, such as Lloydminster, follow Alberta instead.
Following the US dates
Because so much trade and travel crosses the border, most of Canada keeps its DST dates in line with the United States. When the United States lengthened DST from 2007, starting on the second Sunday in March and ending on the first Sunday in November, provinces that observe DST adopted the same dates.
Recent changes
The debate over clock changes is active in Canada. In 2019, British Columbia passed legislation that would allow it to stay on daylight time all year, but only once neighboring US Pacific states do the same. In 2020, Yukon stopped changing its clocks and now stays on UTC−7 all year.
Some local exceptions also persist. For example, Creston in eastern British Columbia keeps Mountain Standard Time all year.
Key dates
| Year | Event |
|---|---|
| 1879 | Sandford Fleming proposes worldwide time zones |
| 1883 | Railways adopt standard time zones |
| 1908 | Port Arthur, Ontario, uses summer time |
| 1949 | Newfoundland joins Canada with its half-hour time |
| 1966 | Saskatchewan Time Act |
| 2007 | Most provinces adopt the extended US DST dates |
| 2020 | Yukon stays on UTC−7 all year |
For current offsets and a map, see the Canada time zones guide. To compare with the south, read the history of US time zones, and check upcoming clock changes on the daylight saving time page.