Timezone converter

MST to JST Converter.

MST → JSTGap: +16hNo 9-5 overlap

MST to JST currently uses Mountain Time in America/Phoenix and Japan Time in Asia/Tokyo as the live reference pair, with a +16h live gap. MST to JST matters whenever Phoenix and Tokyo need to coordinate across a +16h gap. The MST side covers United States and Mexico, while JST covers Japan — that country mix is the practical reason this conversion shows up in calendars rather than the abstract offset math.

Offset math, DST behavior, and city coverage on both sides are refreshed from the live timezone dataset during the page revalidation window.

From

MST

Mountain Time

America/Phoenix · MST -07:00

--:--:--

Major markets in this grouping include Phoenix, Ciudad Juárez, Calgary, Edmonton.

To

JST

Japan Time

Asia/Tokyo · GMT+9 +09:00

--:--:--

Major markets in this grouping include Tokyo, Yokohama, Osaka, Nagoya.

Scheduling snapshot

Current gap

+16h

MST -07:00 vs JST +09:00

9-to-5 overlap

No shared block

Meetings usually need an early or late handoff.

Representative countries

United States, Mexico, and Canada / Japan

Based on the busiest city and zone usage found in the current dataset.

Pair context

MST (Phoenix, -07:00) to JST (Tokyo, +09:00) is currently a +16h conversion. Live coverage on the MST side is anchored by Phoenix, Ciudad Juárez, Calgary, and Edmonton; the JST side draws from Tokyo, Yokohama, Osaka, and Nagoya.

MST to JST matters whenever Phoenix and Tokyo need to coordinate across a +16h gap. The MST side covers United States and Mexico, while JST covers Japan — that country mix is the practical reason this conversion shows up in calendars rather than the abstract offset math.

This pair is trans-Pacific, with one side in the Americas and the other in Asia or Oceania. The +16h gap is large enough that morning on one side reliably overlaps evening on the other, which is why this conversion mostly serves global supply chains, gaming launch schedules, and follow-the-sun engineering.

Neither MST nor JST observes daylight saving on the reference zones used here, so the gap stays steady all year. That makes this pair predictable for recurring meetings, broadcast schedules, and contracts that care about a stable offset.

MST and JST sit exactly 16h apart, which leaves no shared 9-to-5 block. Live meetings have to bend one side's day, so most teams settle for one of two narrow windows: very early on the late side, or very late on the early side. That makes async messages, recorded standups, and clear handoff notes more valuable than calendar invites.

Pair details

Reference zone, current offsets, country and city anchors, overlap math, and date-shift answers for MST to JST.

Reference pair

America/Phoenix -> Asia/Tokyo

Live offsets

MST -07:00 vs JST +09:00

Meaning split

Mountain Time / Japan Time

Country anchors

United States, Mexico, and Canada -> Japan

City anchors

Phoenix, Ciudad Juárez, Calgary, Edmonton -> Tokyo, Yokohama, Osaka, Nagoya

Workday overlap

No strict 9-to-5 overlap in the current offset state

Morning answer

9 AM MST = 1:00 AM JST, next day

Evening answer

6 PM MST = 10:00 AM JST, next day

Calendar and scheduling context

Same-offset labels can share the same hour while still landing in different countries, calendars, cities, and workday windows. These notes show the practical context behind this conversion.

Exact pair identity

MST to JST is pinned to America/Phoenix -> Asia/Tokyo, with the shorthand labels shown as context. The city anchors are Phoenix, Ciudad Juárez, Calgary, Edmonton on the MST side and Tokyo, Yokohama, Osaka, Nagoya on the JST side, with +16h between the live reference zones.

Civil calendar differences

The 12 popular-hour answers include 0 same-day conversions, 12 next-day conversions, and 0 previous-day conversions. That distribution is what separates this page from a static offset chart.

Same-offset caution

Nearby labels sharing a current offset include MDT (From side), GMT-7 (From side), YT (From side), GMT+9 (To side), KST (To side), PWT (To side). They may match mathematically, but their country calendars, city anchors, and common search intent differ from this exact pair.

Jurisdiction evidence

MST: United States (US); 187 mapped cities; capital Washington, D.C.; English; USD United States dollar | MST: Mexico (MX); 1 mapped cities; capital Mexico City; Spanish; MXN Mexican peso | MST: Canada (CA); 34 mapped cities; capital Ottawa; English, French; CAD Canadian dollar | JST: Japan (JP); 1296 mapped cities; capital Tokyo; Japanese; JPY Japanese yen

Pair fingerprint

Offset behavior, DST gap changes, local calendar evidence, and the day-shift pattern across the most common conversion hours.

Offset behavior class

MST/JST is a long-haul handoff gap: America/Phoenix currently reads -07:00, Asia/Tokyo reads +09:00, and the live delta is +16h. This class decides whether the page behaves like a same-day planner or a handoff planner.

DST asymmetry check

America/Phoenix and Asia/Tokyo do not show a detected near-term DST gap-change note in this sample, but the page still exposes exact IANA zones so users do not treat the abbreviation pair as permanently fixed.

Calendar evidence

No country holiday snapshot is attached to this exact pair yet, so the page leans on city anchors, IANA zones, offsets, and the live conversion table instead of pretending a local calendar exists.

Day-shift fingerprint

Across the 12 popular-hour answers, this pair has 0 same-day answers, 12 next-day answers, 0 previous-day answers. That mix is specific to the current America/Phoenix -> Asia/Tokyo relationship and helps users see whether dates must be written explicitly in invites, travel plans, and release schedules.

Same-offset and canonical audit

Same-offset converter clusters can look identical if the page only shows a numeric offset. This audit states whether the route should be indexed, which canonical peer it follows when consolidated, and what pair-specific evidence keeps the page useful.

Indexing posture

This pair remains indexable because the route has enough pair-specific context: America/Phoenix -> Asia/Tokyo, country anchors, city anchors, calendar notes, and day-shift examples.

Same-offset math check

MST and JST are not currently a same-offset pair; the live delta is +16h. Same-offset neighbors are still listed because users often confuse nearby abbreviations.

Neighbor audit

MDT (From side, -07:00), GMT-7 (From side, -07:00), YT (From side, -07:00), GMT+9 (To side, +09:00), KST (To side, +09:00), PWT (To side, +09:00) The page keeps these labels visible so SGT/HKT/GST-style clusters do not blur into one generic offset page.

Canonical evidence

MST/JST uses 0 same-day answers, 12 next-day answers, 0 previous-day answers; 0h strict workday overlap; source zones America/Phoenix and Asia/Tokyo; country anchors United States, Mexico, and Canada -> Japan.

Local intent behind each abbreviation

Common places, calendars, markets, languages, and operating contexts behindMST and JST.

MST

MST local intent 1

MST is Mountain Standard Time, but the label is risky because North American Mountain-region cities do not all behave the same year-round. Denver-style locations can move to MDT while Arizona-style planning often stays on standard time.

MST

MST local intent 2

MST conversions should be pinned to the representative IANA zone before use. The practical context can involve Arizona, the US Mountain region, Canada or Mexico-facing schedules, outdoor tourism, sports broadcasts, and cross-border operations.

JST

JST local intent 1

JST is Japan civil time, centered on Tokyo, Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, and the rest of the Japanese domestic timetable. The useful context is Japan's no-DST posture, yen-denominated business cycles, Tokyo Stock Exchange timing, rail and aviation punctuality, anime/game/media release schedules, and holiday clusters such as Golden Week and year-end closures.

JST

JST local intent 2

A JST conversion is often searched by teams coordinating with Japan specifically, not merely UTC+9. Product launches, live streams, travel arrivals, and support handoffs should account for Japanese business etiquette, local public holidays, and the difference between Japan's stable clock and regions where daylight saving changes the counterpart offset.

Country calendar contrast

Same-offset conversions can still land in different public-holiday, language, currency, and city-anchor contexts. These rows use the country profile and holiday snapshots behind each side of the pair.

MST

United States

187 mapped city anchors; zones America/Phoenix, America/Denver.capital Washington, D.C.; English; USD United States dollar

Holiday snapshot: New Year's Day (Jan 1, Public) · Martin Luther King, Jr. Day (Jan 19, Public) · Lincoln's Birthday (Feb 12, Observance) · Presidents Day (Feb 16, Public) · Good Friday (Apr 3, Public)

MST

Mexico

1 mapped city anchors; zones America/Ciudad_Juarez.capital Mexico City; Spanish; MXN Mexican peso

Holiday snapshot: New Year's Day (Jan 1, Public) · Constitution Day (Feb 2, Public) · Benito Juárez's birthday (Mar 16, Public) · Maundy Thursday (Apr 2, Bank) · Good Friday (Apr 3, Bank)

MST

Canada

34 mapped city anchors; zones America/Edmonton.capital Ottawa; English, French; CAD Canadian dollar

Holiday snapshot: New Year's Day (Jan 1, Public) · Louis Riel Day (Feb 16, Public) · Islander Day (Feb 16, Public) · Heritage Day (Feb 16, Public) · Family Day (Feb 16, Public)

JST

Japan

1,296 mapped city anchors; zones Asia/Tokyo.capital Tokyo; Japanese; JPY Japanese yen

Holiday snapshot: New Year's Day (Jan 1, Public) · Coming of Age Day (Jan 12, Public) · Foundation Day (Feb 11, Public) · The Emperor's Birthday (Feb 23, Public) · Vernal Equinox Day (Mar 20, Public)

Neighboring abbreviation checks

These are the labels most likely to be confused with either side of this conversion. A matching UTC offset does not mean the same country, calendar, market, source convention, or user intent.

From side: MDT

same offset

MST and MDT match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
MDT: Mountain Time via America/Ciudad_Juarez, -07:00; cities Ciudad Juárez, Mexico, Calgary, Canada, and Edmonton, Canada; countries Mexico, Canada, and United States.
Open MDT

From side: GMT-7

same offset

MST and GMT-7 match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
GMT-7: Mexican Pacific Time via America/Hermosillo, -07:00; cities Hermosillo, Mexico, Ciudad Obregón, Mexico, and Nogales, Mexico; countries Mexico.
Open GMT-7

From side: YT

same offset

MST and YT match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
YT: Yukon Time via America/Whitehorse, -07:00; cities Whitehorse, Canada; countries Canada.
Open YT

From side: CDT

nearby

MST and CDT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
CDT: Central Time via America/Chicago, -06:00; cities Chicago, United States, Houston, United States, and San Antonio, United States; countries United States, Canada, and Mexico.
Open CDT

From side: GALT

nearby

MST and GALT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
GALT: Galapagos Time via Pacific/Galapagos, -06:00; cities No country breakdown available; countries Ecuador.
Open GALT

From side: PDT

nearby

MST and PDT are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.

Current side
MST: Mountain Time via America/Phoenix, -07:00; cities Phoenix, United States, Ciudad Juárez, Mexico, and Calgary, Canada; countries United States, Mexico, and Canada.
Neighbor side
PDT: Pacific Time via America/Los_Angeles, -08:00; cities Los Angeles, United States, Tijuana, Mexico, and San Diego, United States; countries United States, Mexico, and Canada.
Open PDT

To side: GMT+9

same offset

JST and GMT+9 match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
GMT+9: Timor-Leste Time via Asia/Dili, +09:00; cities Dili, Timor Leste, Maliana, Timor Leste, and Suai, Timor Leste; countries Timor Leste.
Open GMT+9

To side: KST

same offset

JST and KST match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
KST: Korean Time via Asia/Seoul, +09:00; cities Seoul, South Korea, Busan, South Korea, and Pyongyang, North Korea; countries South Korea and North Korea.
Open KST

To side: PWT

same offset

JST and PWT match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
PWT: Palau Time via Pacific/Palau, +09:00; cities Ngerulmud, Palau; countries Palau.
Open PWT

To side: WIT

same offset

JST and WIT match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
WIT: Eastern Indonesia Time via Asia/Jayapura, +09:00; cities Jayapura, Indonesia, Ambon, Indonesia, and Sorong, Indonesia; countries Indonesia.
Open WIT

To side: YAKT

same offset

JST and YAKT match on offset right now, but the page should not collapse them: they carry different city anchors, country calendars, currencies, holidays, and user intent.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
YAKT: Yakutsk Time via Asia/Chita, +09:00; cities Chita, Russia, Krasnokamensk, Russia, and Borzya, Russia; countries Russia.
Open YAKT

To side: ACWST

nearby

JST and ACWST are close enough to be confused in search, but they are not the same clock label and should be pinned to exact IANA zones.

Current side
JST: Japan Time via Asia/Tokyo, +09:00; cities Tokyo, Japan, Yokohama, Japan, and Osaka, Japan; countries Japan.
Neighbor side
ACWST: Australian Central Western Time via Australia/Eucla, +08:45; cities No country breakdown available; countries Australia.
Open ACWST

Jurisdiction and city roster

Abbreviations with the same UTC offset can still represent different countries, cities, currencies, languages, and civil-time histories. This roster keeps theMST to JST page grounded in those concrete places.

MST: United States (US); 187 mapped cities; zones America/Phoenix, America/Denver; city anchors Phoenix (America/Phoenix, pop 1,650,070), Denver (America/Denver, pop 729,019), El Paso (America/Denver, pop 678,815), Albuquerque (America/Denver, pop 564,559); official United States of America; capital Washington, D.C.; region Americas; subregion North America; population 340,110,988; area 9,525,067 km2; languages English; currency USD United States dollar.

MST: Mexico (MX); 1 mapped cities; zones America/Ciudad Juarez; city anchors Ciudad Juárez (America/Ciudad_Juarez, pop 1,512,450); official United Mexican States; capital Mexico City; region Americas; subregion North America; population 130,575,786; area 1,964,375 km2; languages Spanish; currency MXN Mexican peso.

MST: Canada (CA); 34 mapped cities; zones America/Edmonton; city anchors Calgary (America/Edmonton, pop 1,306,784), Edmonton (America/Edmonton, pop 1,010,899), Lethbridge (America/Edmonton, pop 103,197), Red Deer (America/Edmonton, pop 100,844); official Canada; capital Ottawa; region Americas; subregion North America; population 41,651,653; area 9,984,670 km2; languages English, French; currency CAD Canadian dollar.

JST: Japan (JP); 1296 mapped cities; zones Asia/Tokyo; city anchors Tokyo (Asia/Tokyo, pop 9,733,276), Yokohama (Asia/Tokyo, pop 3,777,491), Osaka (Asia/Tokyo, pop 2,753,862), Nagoya (Asia/Tokyo, pop 2,332,176); official Japan; capital Tokyo; region Asia; subregion Eastern Asia; population 123,210,000; area 377,930 km2; languages Japanese; currency JPY Japanese yen.

Abbreviation identity dossier

Same-offset converter pages can look deceptively alike. These records pin the page to the exact abbreviations, IANA zones, countries, and city anchors behind MST and JST.

From side meaning roster

MST (mst) is not marked ambiguous in the abbreviation catalog. Meaning records: Mountain Time at UTC-07:00; listed zones America/Phoenix; America/Edmonton; America/Ciudad Juarez; America/Denver; source label Mountain Time - Phoenix, Tucson, Mesa, Chandler.

From side country footprint

MST currently maps to 3 country footprints in the converter dataset: United States (US), Mexico (MX), Canada (CA). The footprint spans 4 IANA zones across 10 city anchors.

From side city anchors

MST city anchors in this indexed page family: Phoenix [phoenix-US, US, America/Phoenix, pop 1,650,070]; Ciudad Juárez [ciudad-juarez-MX, MX, America/Ciudad_Juarez, pop 1,512,450]; Calgary [calgary-CA, CA, America/Edmonton, pop 1,306,784]; Edmonton [edmonton-CA, CA, America/Edmonton, pop 1,010,899]; Denver [denver-US, US, America/Denver, pop 729,019]; El Paso [el-paso-US, US, America/Denver, pop 678,815]; Albuquerque [albuquerque-US, US, America/Denver, pop 564,559]; Tucson [tucson-US, US, America/Phoenix, pop 542,629]; Mesa [mesa-US, US, America/Phoenix, pop 471,825]; Colorado Springs [colorado-springs-US, US, America/Denver, pop 456,568].

From side jurisdiction dossier

MST: United States (US); 187 mapped cities; zones America/Phoenix, America/Denver; city anchors Phoenix (America/Phoenix, pop 1,650,070), Denver (America/Denver, pop 729,019), El Paso (America/Denver, pop 678,815), Albuquerque (America/Denver, pop 564,559); official United States of America; capital Washington, D.C.; region Americas; subregion North America; population 340,110,988; area 9,525,067 km2; languages English; currency USD United States dollar. MST: Mexico (MX); 1 mapped cities; zones America/Ciudad Juarez; city anchors Ciudad Juárez (America/Ciudad_Juarez, pop 1,512,450); official United Mexican States; capital Mexico City; region Americas; subregion North America; population 130,575,786; area 1,964,375 km2; languages Spanish; currency MXN Mexican peso. MST: Canada (CA); 34 mapped cities; zones America/Edmonton; city anchors Calgary (America/Edmonton, pop 1,306,784), Edmonton (America/Edmonton, pop 1,010,899), Lethbridge (America/Edmonton, pop 103,197), Red Deer (America/Edmonton, pop 100,844); official Canada; capital Ottawa; region Americas; subregion North America; population 41,651,653; area 9,984,670 km2; languages English, French; currency CAD Canadian dollar.

To side meaning roster

JST (jst) is not marked ambiguous in the abbreviation catalog. Meaning records: Japan Time at UTC+09:00; listed zones Asia/Tokyo; source label Japan Time - Tokyo, Yokohama, Osaka, Nagoya.

To side country footprint

JST currently maps to 1 country footprint in the converter dataset: Japan (JP). The footprint spans 1 IANA zone across 10 city anchors.

To side city anchors

JST city anchors in this indexed page family: Tokyo [tokyo-JP, JP, Asia/Tokyo, pop 9,733,276]; Yokohama [yokohama-JP, JP, Asia/Tokyo, pop 3,777,491]; Osaka [osaka-JP, JP, Asia/Tokyo, pop 2,753,862]; Nagoya [nagoya-JP, JP, Asia/Tokyo, pop 2,332,176]; Sapporo [sapporo-JP, JP, Asia/Tokyo, pop 1,973,832]; Fukuoka [fukuoka-JP, JP, Asia/Tokyo, pop 1,612,392]; Kawasaki [kawasaki-JP, JP, Asia/Tokyo, pop 1,538,262]; Kobe [kobe-JP, JP, Asia/Tokyo, pop 1,525,152]; Kyoto [kyoto-JP, JP, Asia/Tokyo, pop 1,463,723]; Saitama [saitama-JP, JP, Asia/Tokyo, pop 1,324,854].

To side jurisdiction dossier

JST: Japan (JP); 1296 mapped cities; zones Asia/Tokyo; city anchors Tokyo (Asia/Tokyo, pop 9,733,276), Yokohama (Asia/Tokyo, pop 3,777,491), Osaka (Asia/Tokyo, pop 2,753,862), Nagoya (Asia/Tokyo, pop 2,332,176); official Japan; capital Tokyo; region Asia; subregion Eastern Asia; population 123,210,000; area 377,930 km2; languages Japanese; currency JPY Japanese yen.

From side timezone narrative

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.

From side policy and precision notes

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.

From side nearby abbreviations

MST should not be blindly swapped with nearby labels. Adjacent references in the catalog: MDT (-07:00, Shares the mountain time family); GMT-7 (-07:00, Currently sits on the same UTC offset); YT (-07:00, Currently sits on the same UTC offset); CDT (-06:00, Runs on a nearby UTC offset); GALT (-06:00, Runs on a nearby UTC offset); PDT (-08:00, Runs on a nearby UTC offset).

From side answer profile

MST has 1 meaning record, offset range UTC-07:00 to UTC-06:00, labels Mountain Time, and 3 country footprints across 4 IANA zones.

To side timezone narrative

JST is an Asian civil-time label, currently 9h ahead of UTC at +09:00. The lead reference is Tokyo, and the wider grouping reaches 1 country through 1 IANA zone. The busiest cities using JST in the current catalog are Tokyo, Yokohama, Osaka, Nagoya, and Sapporo. The lead live reference on this page is Tokyo (Asia/Tokyo), currently at +09:00 (GMT+9). Those cities are what give JST its actual feel rather than the abstract offset. JST is stable on Asia/Tokyo 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.

To side policy and precision notes

JST resolves cleanly here, but Asian labels often share letters with American or European ones — IST is shared between India and Israel, for instance. Pinning Asia/Tokyo avoids that whole class of confusion. Asia/Tokyo does not show an offset change in the next year, which makes JST 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 JST is the exact IANA zone used by your city or system. Asia/Tokyo sits at +09:00, ahead of UTC, which means daily logs in this zone reach a new calendar date before UTC does — a small detail that breaks date-based reporting if missed.

To side nearby abbreviations

JST should not be blindly swapped with nearby labels. Adjacent references in the catalog: GMT+9 (+09:00, Currently sits on the same UTC offset); KST (+09:00, Currently sits on the same UTC offset); PWT (+09:00, Currently sits on the same UTC offset); WIT (+09:00, Currently sits on the same UTC offset); YAKT (+09:00, Currently sits on the same UTC offset); ACWST (+08:45, Runs on a nearby UTC offset).

To side answer profile

JST has 1 meaning record, offset range UTC+09:00, labels Japan Time, and 1 country footprint across 1 IANA zone.

From side country reference summary

MST country anchor United States: The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic consisting of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 341 million. Source: Wikipedia.

To side country reference summary

JST country anchor Japan: Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asian mainland, it is bordered to the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea in the south. The Japanese archipelago consists of four major islands alongside 14,121 smaller islands. Japan is divided into 47 administrative prefectures and eight traditional regions, and around 75% of its terrain is mountainous and heavily forested, concentrating its agriculture and highly urbanized population along its eastern coastal plains. With a population of almost 123 million as of 2026, it is the world's 11th most populous country. Tokyo is the country's capital and largest city. Source: Wikipedia.

From side trust note 1

MST is Mountain Standard Time, but the label is risky because North American Mountain-region cities do not all behave the same year-round. Denver-style locations can move to MDT while Arizona-style planning often stays on standard time.

From side trust note 2

MST conversions should be pinned to the representative IANA zone before use. The practical context can involve Arizona, the US Mountain region, Canada or Mexico-facing schedules, outdoor tourism, sports broadcasts, and cross-border operations.

To side trust note 1

JST is Japan civil time, centered on Tokyo, Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, and the rest of the Japanese domestic timetable. The useful context is Japan's no-DST posture, yen-denominated business cycles, Tokyo Stock Exchange timing, rail and aviation punctuality, anime/game/media release schedules, and holiday clusters such as Golden Week and year-end closures.

To side trust note 2

A JST conversion is often searched by teams coordinating with Japan specifically, not merely UTC+9. Product launches, live streams, travel arrivals, and support handoffs should account for Japanese business etiquette, local public holidays, and the difference between Japan's stable clock and regions where daylight saving changes the counterpart offset.

Pair identity check

MST/JST uses America/Phoenix -> Asia/Tokyo, offset delta +16h, overlap 0h, route /convert/mst/jst/, and live abbreviation readings MST/GMT+9.

Market coverage on both sides

MST coverage on this page is led by Phoenix, United States, Ciudad Juárez, Mexico, Calgary, Canada, and Edmonton, Canada, with 2 more in the live dataset. That mix is what makes MST feel anchored to West Coast and Pacific-edge American activity in practice rather than just an abbreviation on a chart.

JST coverage is led by Tokyo, Japan, Yokohama, Japan, Osaka, Japan, and Nagoya, Japan, with 2 more anchoring the wider label family. Combined with the MST side, this conversion ends up describing trans-Pacific outsourcing handoffs, gaming and entertainment release windows, and follow-the-sun engineering rotations.

Digit-roll converter

Adjust the time. Digits roll like an odometer, and the swap button flips the zones.

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That is the next day in Tokyo.

Common meeting times

MST to JST meeting times

Quick conversions for 9 AM, noon, 3 PM, 6 PM, and 9 PM based on today's local calendar.

MSTJSTDay relation
9:00 AM1:00 AMFri, Nov 6next day
12:00 PM4:00 AMFri, Nov 6next day
3:00 PM7:00 AMFri, Nov 6next day
6:00 PM10:00 AMFri, Nov 6next day
9:00 PM1:00 PMFri, Nov 6next day

JST to MST meeting times

Quick conversions for 9 AM, noon, 3 PM, 6 PM, and 9 PM based on today's local calendar.

JSTMSTDay relation
9:00 AM5:00 PMThu, Nov 5previous day
12:00 PM8:00 PMThu, Nov 5previous day
3:00 PM11:00 PMThu, Nov 5previous day
6:00 PM2:00 AMFri, Nov 6same day
9:00 PM5:00 AMFri, Nov 6same day

Operational notes

MST to JST ranges from MST 9:00 AM (which lands at JST 1:00 AM) through MST 9:00 PM (JST 1:00 PM). Most of those slots fall on a different calendar day on the JST side, which is why this direction always needs explicit dates in invites and ticket comments — the time alone is not enough.

JST to MST ranges from JST 9:00 AM (which lands at MST 5:00 PM) through JST 9:00 PM (MST 5:00 AM). Most of those slots fall on a different calendar day on the MST side, which is why this direction always needs explicit dates in invites and ticket comments — the time alone is not enough.

Popular hour answers

These direct answers are here for the exact-intent searches people actually use, like “10 AM MST to JST” or “4 PM MST in JST”.

What is 8 AM MST in JST?

8 AM MST = 12:00 AM JST (00:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 9 AM MST in JST?

9 AM MST = 1:00 AM JST (01:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 10 AM MST in JST?

10 AM MST = 2:00 AM JST (02:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 11 AM MST in JST?

11 AM MST = 3:00 AM JST (03:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 12 PM MST in JST?

12 PM MST = 4:00 AM JST (04:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 1 PM MST in JST?

1 PM MST = 5:00 AM JST (05:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 2 PM MST in JST?

2 PM MST = 6:00 AM JST (06:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 3 PM MST in JST?

3 PM MST = 7:00 AM JST (07:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 4 PM MST in JST?

4 PM MST = 8:00 AM JST (08:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 5 PM MST in JST?

5 PM MST = 9:00 AM JST (09:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 6 PM MST in JST?

6 PM MST = 10:00 AM JST (10:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

What is 9 PM MST in JST?

9 PM MST = 1:00 PM JST (13:00). On today's live calendar that lands on Fri, Nov 6 in JST, which means the answer is a next day conversion rather than a static offset lookup.

Overlap window and DST radar

The live gap is +16h right now, based on America/Phoenix at -07:00 and Asia/Tokyo at +09:00. Neither reference zone shows an offset change in the next year, so the gap should stay stable.

There is no strict 9 AM to 5 PM overlap right now, so this pair is better for handoffs, travel planning, or async coordination than for midday meetings.

Reference zones

America/Phoenix

MST · -07:00

Asia/Tokyo

GMT+9 · +09:00

These are the busiest live references selected from the abbreviation families on this page.

Conversion Table

MSTJST
17:0009:00
18:0010:00
19:0011:00
20:0012:00
21:0013:00
22:0014:00
23:0015:00
00:0016:00
01:0017:00
02:0018:00
03:0019:00
04:0020:00
05:0021:00
06:0022:00
07:0023:00
08:0000:00
09:0001:00
10:0002:00
11:0003:00
12:0004:00
13:0005:00
14:0006:00
15:0007:00
16:0008:00

Top cities using JST

Countries represented here include Japan.

FAQ

How many hours is JST ahead of MST?
JST is currently +16h relative to MST, using America/Phoenix and Asia/Tokyo as the live reference zones on this page.
What is the best workday overlap between MST and JST?
There is no strict 9-to-5 overlap right now, so one side usually needs an early start or late finish for live meetings.
Does the MST-JST time difference change during DST?
The live gap is +16h right now, based on America/Phoenix at -07:00 and Asia/Tokyo at +09:00. Neither reference zone shows an offset change in the next year, so the gap should stay stable.
Which cities commonly use MST and JST?
MST commonly covers cities such as Phoenix, Ciudad Juárez, Calgary, and Edmonton, while JST commonly covers cities such as Tokyo, Yokohama, Osaka, and Nagoya.
Should I use MST/JST or exact IANA zones?
Use the abbreviations for a quick read, but use exact IANA zones such as America/Phoenix and Asia/Tokyo when you need something precise in software, travel plans, or long-range scheduling.
Open Interactive Converter

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