Does Mountain Time cross the US, Canada border without a clock change?
At Sweetgrass, Montana and Coutts, Alberta, the answer is yes. Both towns run on the same clock. When it is 10:00 AM in Sweetgrass, it is 10:00 AM in Coutts.
Canada and the United States use the same DST schedule: clocks spring forward on the second Sunday in March and fall back on the first Sunday in November. A driver crossing at Sweetgrass, Coutts never adjusts their watch. The same holds at other Mountain Time crossings between Montana and Alberta.
The reason is practical. Alberta and Montana share a border built around cross‑border farming, trade, and family. A time difference would cost money. So they match.
El Paso and Ciudad Juárez: two cities, one clock
The border between El Paso, Texas (population 678,815) and Ciudad Juárez, Mexico (population 1,512,450) is the largest binational urban area in the Mountain Time zone. They are on the same time, by design.
El Paso uses the IANA zone America/Denver. Ciudad Juárez uses America/Ciudad_Juarez. Both follow the same DST rules: spring forward in March, fall back in November. When El Paso goes to MDT (UTC−6), so does Juárez.
People cross here daily for work, school, and shopping. If the clocks did not match, a shift starting at 8:00 AM in Juárez would start at 9:00 AM in El Paso. That is not what happens.
For a detailed look at Juárez time specifically, see Time in Ciudad Juárez.
Mexico abolished DST in 2022. Why does Juárez still change?
In October 2022, Mexico abolished daylight saving time nationally. The change took effect in 2023. Most of Mexico now stays on standard time year-round.
But municipalities bordering the United States got an exception. Ciudad Juárez is one of them. The Mexican government lets these border towns keep DST so they stay aligned with their US neighbours. Juárez matches El Paso.
That makes Ciudad Juárez the only place in Mexico that still changes its clocks. It follows the US DST schedule, not the Mexican one.
Why do Dawson Creek, Fort Nelson, and Lloydminster break the pattern?
Canada's time zones are set by provincial legislation, not federal law. That creates three distinct Mountain Time situations.
Alberta uses Mountain Time with DST. So do the Northwest Territories and Nunavut's western Kitikmeot Region. The province held a referendum on permanent DST in 2021; 50.2% voted against it. For now, Alberta stays on the standard US pattern.
British Columbia is mostly on Pacific Time, but two towns in the Peace River region are on Mountain Time and do not observe DST: Dawson Creek and Fort Nelson. They stay on MST (UTC−7) year-round. In summer, Dawson Creek is one hour behind the rest of Mountain Time, which is on MDT (UTC−6). In winter, it matches.
Saskatchewan is mostly on Central Standard Time (UTC−6) year-round, with no DST. But the city of Lloydminster straddles the border with Alberta. Lloydminster follows Alberta time: Mountain Time with DST. Saskatchewan's CST matches Alberta's MDT in summer, and runs one hour ahead of Alberta's MST in winter.
For the exact time in Calgary, see Time in Calgary. For Edmonton, see Time in Edmonton.
What should I check before a Mountain Time call between the US, Canada, and Mexico?
If you work across a Mountain Time border, here is what you need to know.
| Border | Time match? | DST match? | Notes |
|---|---|---|---|
| US, Canada (MT crossings) | Yes | Yes | Sweetgrass/Coutts, Montana/Alberta |
| US, Mexico (El Paso/Juárez) | Yes | Yes | Juárez kept DST by exception |
| US, Canada (BC Peace) | Depends on season | No | Dawson Creek stays MST year-round |
| Canada internal (Lloydminster) | Yes | Yes | Follows Alberta, not Saskatchewan |
The biggest trap is summer scheduling with British Columbia's Peace region. A 2:00 PM meeting in Denver is 2:00 PM in Edmonton but 1:00 PM in Dawson Creek. That is not obvious unless you know the exception.
Travel tips for crossing Mountain Time borders
- Sweetgrass, Coutts: No change. Your phone handles it.
- El Paso, Juárez: No change. Both sides use MDT in summer, MST in winter.
- Dawson Creek or Fort Nelson: Check the season. In summer, they are one hour behind the rest of Mountain Time. In winter, they match.
- Lloydminster: It is on Alberta time. Do not assume Saskatchewan time when you cross the city border.
For the full list of Mountain Time states and provinces, see Which States Are in the Mountain Time Zone?.
When does Mountain Time next change its clocks?
The next clock change for most of Mountain Time is Sunday 01 November 2026 at 02:00 local. Clocks go back 60 minutes to 01:00, and MDT (UTC−6) becomes MST (UTC−7). That applies to Denver, Calgary, Edmonton, El Paso, and Ciudad Juárez.
It does not apply to Phoenix, Dawson Creek, or Fort Nelson. They stay on MST year-round. And it does not apply to most of Mexico, which abolished DST in 2022.
For the full DST schedule, see MST Daylight Saving Time: Dates, Rules, and Exceptions.
For why Arizona never changes, see Why Doesn't Arizona Observe Daylight Saving Time?.