Timezone abbreviation
MST currently resolves here through America/Phoenix, where the live offset is -07:00 (MST). This page expands that into the broader meaning set, top cities, countries, similar labels, and safer exact-zone equivalents.
Representative zones, offset ranges, and city usage are refreshed from the current timezone dataset so abbreviation pages stay tied to real zones instead of static boilerplate.
MST is a North or South American civil-time label, currently 7h behind UTC at -07:00. The label covers 4 IANA zones across 3 countries, with Phoenix as the busiest live reference.
The busiest cities using MST in the current catalog are Phoenix, Ciudad Juárez, Calgary, Edmonton, and Denver. The lead live reference on this page is Phoenix (America/Phoenix), currently at -07:00 (MST). Those cities are what give MST its actual feel rather than the abstract offset.
MST is stable on America/Phoenix year-round, with no seasonal clock changes in the next year. That makes it a low-friction choice for recurring meetings and broadcast schedules — but software still prefers the IANA zone because governments can change civil-time rules independently of the short code.
Live reference
America/Phoenix
Current offset
-07:00 (MST)
Meanings / zones / countries
1 / 4 / 3
Offset range
UTC-07:00 to UTC-06:00
MST is a North American mainland-style offset, so it overlaps with the US and Canadian business day. In practice it is read inside North America, where the leading city anchors are Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada.
MST maps to a single conceptual meaning, but it spans 4 IANA zones — small DST and historical-rule differences between those zones are why timestamp systems should still pin to the exact zone.
MST shows up on broadcast guides, sports schedules, and inter-state corporate calendars. MST stays on a single offset year-round in the current data, which simplifies its operational use.
Zone family, representative city, current offset, country coverage, and nearby abbreviation context for MST.
Primary zone
America/Phoenix
Live offset
-07:00 · MST
Region family
North America
Meaning count
1 meaning
Zone / country reach
4 zones · 3 countries
Representative city
Phoenix, United States
Country anchor
United States
DST posture
No upcoming seasonal clock change detected in the representative zone
Offset range
UTC-07:00 to UTC-06:00
Data fingerprint
This compact fingerprint is intentionally specific: exact zone IDs, place anchors, country anchors, transition cues, and offset peers. It gives humans and crawlers concrete reasons not to collapse MSTinto another abbreviation with the same clock hour.
Route identity
mst · MST · Mountain Time · America/Phoenix
Exact IANA zone set
America/Phoenix, America/Edmonton, and America/Ciudad_Juarez
Place anchors
Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada
Country anchors
United States (America/Phoenix, America/Denver), Mexico (America/Ciudad_Juarez), and Canada (America/Edmonton)
Transition fingerprints
America/Phoenix: no next-year switch, America/Edmonton: no next-year switch, and America/Ciudad_Juarez: MST-MDT on March 14, 2027
Offset peers to verify
GMT-7 (America/Hermosillo), MDT (America/Ciudad_Juarez), YT (America/Whitehorse)
Abbreviation dossier
These checks separate the abbreviation from lookalike labels and same-offset codes: the representative IANA zone, the current civil-time reading, the city/country footprint, and whether the lead zone has an upcoming clock change.
Primary live reading
Mountain Time resolves through America/Phoenix right now: -07:00 (MST).
Ambiguity status
MST maps to one meaning in this catalog, but the IANA zone still matters because clock-change rules live on the zone, not the short code.
DST and transition posture
America/Phoenix has no scheduled offset switch in the next year in this snapshot.
Country and city reach
MST is represented across 3 countries, 4 IANA zones, and lead cities including Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada.
Same-offset caution
MST and MDT currently share -07:00, but they point at different civil-time labels, cities, countries, and source contexts. Treat the matching offset as arithmetic only, not semantic equivalence.
Editorial check
Mountain-time reading: Use America/Denver for Mountain cities that observe daylight saving.
Precision layer
Timezone abbreviations are useful display labels, but they are weak storage keys. This register shows the exact risks for MST: ambiguity, seasonal changes, same-offset neighbors, and the safer value to store in software, calendars, or operations notes.
Abbreviation ambiguity risk
MediumMST has one meaning in this catalog, but the zone and country context still carry the legal-time rule.
Seasonal clock-change risk
LowAmerica/Phoenix is stable for the next-year transition scan, so the main risk is policy change or same-offset confusion.
Same-offset confusion risk
Medium3 other abbreviation pages currently share -07:00; the same clock hour is not the same civil-time context.
Storage recommendation
Use exact zoneStore America/Phoenix or a UTC instant. Display MST only as a human-facing label after the exact zone is known.
Coverage breadth
4 zonesMST covers 4 IANA zones and 3 country groupings in this page's retained dataset.
Four fixed UTC checkpoints expose whether MST crosses a local date boundary in America/Phoenix. This is the practical difference between a harmless clock conversion and a deadline, release, travel, or reporting mistake.
MST moves this checkpoint to the previous local date in America/Phoenix, which matters for reports, releases, travel, and deadline wording.
MST keeps this checkpoint on the same calendar date as UTC in America/Phoenix.
MST keeps this checkpoint on the same calendar date as UTC in America/Phoenix.
MST keeps this checkpoint on the same calendar date as UTC in America/Phoenix.
These abbreviation pages currently share -07:00with MST. They can show the same wall-clock hour while pointing at different countries, holidays, market calendars, languages, airports, and legal-time rules.
Mexican Pacific Time
GMT-7 shares the current UTC offset with MST, but it is anchored to America/Hermosillo and Mexico. Treat the shared offset as arithmetic only, not as the same holidays, cities, market calendars, or policy context.
Mountain Time
MDT shares the current UTC offset with MST, but it is anchored to America/Ciudad_Juarez and Mexico, Canada, and United States. Treat the shared offset as arithmetic only, not as the same holidays, cities, market calendars, or policy context.
Yukon Time
YT shares the current UTC offset with MST, but it is anchored to America/Whitehorse and Canada. Treat the shared offset as arithmetic only, not as the same holidays, cities, market calendars, or policy context.
The hardest abbreviation mistakes happen when two labels share a similar offset. This matrix spells out what changes when the neighboring label is actually a different civil clock, city cluster, or source context.
MST and MDT currently share -07:00, but they point at different civil-time labels, cities, countries, and source contexts. Treat the matching offset as arithmetic only, not semantic equivalence.
MST and GMT-7 currently share -07:00, but they point at different civil-time labels, cities, countries, and source contexts. Treat the matching offset as arithmetic only, not semantic equivalence.
MST and YT currently share -07:00, but they point at different civil-time labels, cities, countries, and source contexts. Treat the matching offset as arithmetic only, not semantic equivalence.
MST and CDT sit near each other in the catalog, but the live offset and representative-zone context differ. Use the exact IANA zone before storing or sharing the time.
MST and GALT sit near each other in the catalog, but the live offset and representative-zone context differ. Use the exact IANA zone before storing or sharing the time.
MST and PDT sit near each other in the catalog, but the live offset and representative-zone context differ. Use the exact IANA zone before storing or sharing the time.
Editorial disambiguation
MST is Mountain Standard Time at UTC-7, but it is easy to misuse because some Mountain-region places switch to daylight time while places such as Arizona often stay on standard time. This page should be read as a North American mountain-region reference, not a guarantee that every listed city is on the same seasonal rule all year.
United States sits in Americas, specifically North America. Population 340,110,988, area 9,525,067 km², capital Washington, D.C.. Civic markers behind MST include English and USD (United States dollar, $).
United States is linked as the country-level reference source for MST; the civic context above is drawn from structured country fields rather than copied reference prose.
MST in the Mountain Time meaning runs 7h behind UTC through North America, threading zones such as America/Phoenix, America/Edmonton, and America/Ciudad_Juarez (cities: Phoenix, Ciudad Juárez, and Calgary). Country anchors: United States, Mexico, and Canada.
Mountain Time
Current reading: MST at -07:00 in United States.
America/Phoenix does not show a scheduled offset change in the next year, so the current offset can be treated as operationally stable for short-term planning.
City anchors include Phoenix, Ciudad Juárez, and Calgary, while country anchors include United States, Mexico, and Canada.
Mountain Time
Current reading: MDT at -06:00 in Canada.
America/Edmonton does not show a scheduled offset change in the next year, so the current offset can be treated as operationally stable for short-term planning.
City anchors include Phoenix, Ciudad Juárez, and Calgary, while country anchors include United States, Mexico, and Canada.
Mountain Time
Current reading: MST at -07:00 in Mexico.
America/Ciudad_Juarez changes on March 14, 2027 at about 3:00 AM, moving from MST (-07:00) to MDT (-06:00).
City anchors include Phoenix, Ciudad Juárez, and Calgary, while country anchors include United States, Mexico, and Canada.
Mountain Time
Current reading: MST at -07:00 in United States.
America/Denver changes on March 14, 2027 at about 3:00 AM, moving from MST (-07:00) to MDT (-06:00).
City anchors include Phoenix, Ciudad Juárez, and Calgary, while country anchors include United States, Mexico, and Canada.
Live reference zone: America/Phoenix (MST, -07:00)
Leading city in the current dataset: Phoenix, United States.
Cities: Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada. Countries: United States, Mexico, and Canada.
Live zones: America/Phoenix (-07:00), America/Edmonton (-06:00), and America/Ciudad_Juarez (-07:00).
Countries
United States, Mexico, Canada
Top cities
Phoenix, Ciudad Juárez, Calgary, Edmonton
United States spans 2 zones (187 cities) under MST. Visible cities: Phoenix, Denver, and El Paso. Underlying zones: America/Phoenix and America/Denver.
Mexico runs on a single zone (1 mapped cities) under MST. Visible cities: Ciudad Juárez. Underlying zones: America/Ciudad Juarez.
Canada spans 1 zone (34 cities) under MST. Visible cities: Calgary, Edmonton, and Lethbridge. Underlying zones: America/Edmonton.
City anchors for MST (North America, currently -07:00). Pick a city to drop into a live local clock.
United States
Cities: Phoenix, Denver, El Paso, Albuquerque
Meaning group: Mountain Time
Mexico
Cities: Ciudad Juárez
Meaning group: Mountain Time
Canada
Cities: Calgary, Edmonton, Lethbridge, Red Deer
Meaning group: Mountain Time
MST reads cleanly across the Americas in this dataset, but the same letters can mean different things elsewhere (notably CST, EST, and IST overlap with non-American labels). Pin the IANA zone when the audience is international.
America/Phoenix does not show an offset change in the next year, which makes MST predictable for short-term scheduling. Predictable is not the same as permanent — civil-time rules still get changed by governments on relatively short notice.
For precise work, the safest equivalent of MST is the exact IANA zone used by your city or system. America/Phoenix sits at -07:00, behind UTC, which means daily logs in this zone reach a new calendar date after UTC does — relevant for date-aligned reports and billing cutoffs.
Even with one canonical meaning, MST spans 4 IANA zones — pin to America/Phoenix when DST or historical-rule precision matters.
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