American Daylight Time

Canada
Canada follows time zones similar to the ones found in the US. At the beginning of 2026 four areas of Canada followed a time zone that is effectively "permanent DST" (clocks moved forward before ending the seasonal changes).

In 2026 additional provinces and territories of Canada have moved to extend "permanent DST" to cover all of western Canada from Saskatchewan west to the border with Alaska. A US move to "permanent DST" would match these changes. Eastern provinces have expressed the desire to move to "permanent DST" in coordination with neighboring US states.

Based on active proposals the entire western half of Canada will be on Permanent DST at the end of 2026. (Areas shaded above.)

Detailed Canadian History - Canadian moves to Permanent DST
Year of change:
1960/1972 Saskatchewan; 1972 Dawson Creek BC; 1973 Yukon -08; 1980 Yukon PST/PDT; 2015 Fort Nelson BC; 2020 Yukon -07;
2026 British Columbia -07 (March); 2026 Alberta -06 (June); Northwest Territories, Cambridge Bay NU -06 (November?);

Mexico
As of November 2022, most of Mexico no longer follows daylight saving time.
The main central part of Mexico follows "Zona Centro" (UTC-06) with cities near the US border allowed to follow US time zones. The western portion of Mexico follows "Zona Pacifico" (UTC-07). Baja California currently follows US PST/PDT ("Zona Noroeste") and the southeast Mexico state of Quintana Roo follows "Zona Sureste" (UTC-05).

If the Sunshine Protection Act passes in the United States the time zones will align as shown. This map assumes Baja California will follow California's new definition of -7 and Arizona will remain in their current -7 time zone. Any adjustments in central Mexico (where UTC -5 in the US will be north of UTC -6 in Mexico) is unknown.

Name Coordination

Name	HST	AKST	PST	MST	CST	EST	AST
The National Research Council Canada (NRCC) refers to time zones based on the following definitions:
		UTC-08	UTC-07	UTC-06	UTC-05	UTC-04	UTC-03
		Pacific	Mountain	Central	Eastern	Atlantic
Winter		PST	MST	CST	EST	AST
			Pacific	Mountain	Central	Eastern	Atlantic
Summer			PDT	MDT	CDT	EDT	ADT
As of 2022, NRCC refers to the time in Saskatchewan (UTC-06 year round) as CST in winter and MDT in summer (with a note that UTC-06 is also called CST). NRCC refers to the time in Yukon and eastern British Columbia (UTC-07 year round) as MST in winter and PDT in summer (with a note that UTC-07 is also called YST "Yukon Standard Time"). (YST was originally UTC-09. Newfoundland Standard Time (NST) is UTC-03:30. Newfoundland Daylight Time (NDT) is UTC-2:30.) (NRCC - National Research Council Canada)
Mexico uses similar definitions: (unused definitions removed)
		UTC-08	UTC-07	UTC-06	UTC-05
		Zona Noroeste	Zona Pacifico	Zona Centro	Zona Sureste
Standard		PST	MST	CST	EST
DST			PDT
(PST/PDT is used in Baja California matching US PST/PDT. Note the abbreviations do not match the Spanish language names.)
The United States currently uses the same definitions as Canada and Mexico but intends to change those definitions as part of the Sunshine Protection Act. The new definitions would be:
	Zone 7	Zone 6	Zone 5	Zone 4	Zone 3	Zone 2	Zone 1
New Offset	UTC-09	UTC-08	UTC-07	UTC-06	UTC-05	UTC-04	UTC-03
This change would create a conflict with the Canadian and Mexican definitions. In addition, if Arizona chooses to stay on UTC-07 they would remain on an MST defined differently than the rest of the US. If Puerto Rico chooses to stay on UTC-04 they would remain on an AST defined differently than Canada and the US Space Force Base in Greenland. (Hawaii can choose to remain on UTC-10 creating two definitions of Hawaii-Aleutian standard time.)