Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

Denver to Tokyo

+15h

Denver

MDTSOURCE

USA · UTC-06:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Tokyo

JST

Japan · UTC+09:00

HH03

MM00

(next day)03:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Denver

Tokyo

12:00 AM

3:00 PM

2:00 AM

5:00 PM

4:00 AM

7:00 PM

6:00 AM

9:00 PM

8:00 AM

11:00 PM

10:00 AM

1:00 AM+1

12:00 PM

3:00 AM+1

2:00 PM

5:00 AM+1

4:00 PM

7:00 AM+1

6:00 PM

9:00 AM+1

8:00 PM

11:00 AM+1

10:00 PM

1:00 PM+1

Green rows indicate typical business hours (9 AM - 5 PM)

MDT and JST on the World Map

The map below highlights the MDT (Mountain Standard Time) and JST (Japan Standard Time) timezone regions across the globe.

MDT Zone

→

JST Zone

Explore all world timezones interactively →

MST – Mountain Standard Time

UTC-07:00

Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.

Countries in MST

United States (Mountain)Canada (Alberta)Mexico (Chihuahua, Sonora)

Major Cities in MST

DenverPhoenixSalt Lake CityCalgaryEdmontonAlbuquerqueEl PasoTucsonBoiseCiudad Juárez

Key Facts about MST

•Arizona does not observe daylight saving time, staying on MST year-round.
•The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
•Denver, the 'Mile High City', is the largest city fully in MST.
•MST covers 6 US states entirely and parts of several others.

Daylight Saving:Yes – switches to MDT

Learn more about MST on Wikipedia

JST – Japan Standard Time

UTC+09:00

Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.

Countries in JST

Japan

Major Cities in JST

TokyoOsakaYokohamaNagoyaSapporoKyotoKobeFukuokaHiroshima

Key Facts about JST

•Japan does not observe daylight saving time.
•Tokyo is the most populous metropolitan area in the world.
•The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
•JST is 14 hours ahead of EST and 9 hours ahead of GMT.

Daylight Saving:No – UTC+09:00 year-round

Learn more about JST on Wikipedia

About Denver

Wikipedia

Denver operates on Mountain Time (MST/MDT), 2 hours behind New York. As a tech and aerospace hub, Denver bridges West Coast and Central US business hours.

Population:715,000

Metro:2.9 million

Business Hours:8:00 AM - 5:00 PM MST

Currency:USD ($)

Key Landmarks

Red Rocks AmphitheatreDenver Art MuseumUnion Station16th Street MallColorado State Capitol

Did You Know?

Denver International Airport is the largest airport in North America by land area.

Learn more about MDT timezone →

About Tokyo

Wikipedia

Tokyo operates on Japan Standard Time (JST), which is 14 hours ahead of New York. As Asia's largest financial hub, Tokyo trading hours are crucial for global markets.

Population:14 million

Metro:37.4 million

Business Hours:9:00 AM - 6:00 PM JST

Currency:JPY (¥)

Stock Exchange:TSE (Tokyo Stock Exchange)

Key Landmarks

Tokyo TowerShibuya CrossingSenso-ji TempleImperial PalaceTokyo Skytree

Did You Know?

The Tokyo subway system moves approximately 8.7 million passengers daily.

Learn more about JST timezone →

Denver vs Tokyo: Offsets, DST and Best Call Times

Denver runs on Mountain Daylight Time (MDT) at UTC-06:00, currently observing daylight saving time. Tokyo runs on Japan Standard Time (JST) at UTC+09:00. That puts Denver 15 hours ahead of Tokyo — a difference of +15h at the current offsets.

In practice, when it is 9:00 AM in Denver it is 12:00 AM in Tokyo on the next day. Midnight in Denver is 3:00 PM in Tokyo.Denver observes daylight saving time while Tokyo does not, so the gap narrows or widens by an hour part of the year.

Denver to Tokyo time conversion table

Denver (MDT)	Tokyo (JST)	Day
12:00 AM	3:00 PM	same day
6:00 AM	9:00 PM	same day
7:00 AM	10:00 PM	same day
8:00 AM	11:00 PM	same day
9:00 AM	12:00 AM	next day
12:00 PM	3:00 AM	next day
3:00 PM	6:00 AM	next day
5:00 PM	8:00 AM	next day
6:00 PM	9:00 AM	next day
9:00 PM	12:00 PM	next day

Why people convert Denver to Tokyo time

Scheduling a call from Denver to Tokyo: a 10:00 AM start in Denver lands at 1:00 AM in Tokyo the next day, so you can confirm the slot without doing the arithmetic yourself.
Handling a +15h gap: Denver and Tokyo have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in Tokyo is 12:00 AM in Denver.
Coordinating a Denver-based team with Tokyo contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.

Always state the zone abbreviation, not just the hour. "3:00 PM MDT" is unambiguous; "3 PM" across a +15h gap is not.
With a +15h gap there is no shared 9-to-5 window, so alternate the early start: one week Denver takes the early slot, the next week Tokyo does.
Denver: Clocks fall back on Sun, Nov 1, 2026. Re-check this page after that date because the offset changes and so does the +15h gap.

About MST (Mountain Standard Time)

Mountain Standard Time (MST) covers the Rocky Mountain region of the United States and Canada. Arizona is notable for not observing daylight saving time, staying on MST year-round (except the Navajo Nation). The time zone includes major cities like Denver, Phoenix, Calgary, and Salt Lake City. During summer, most areas switch to Mountain Daylight Time (MDT, UTC-06:00).

About JST (Japan Standard Time)

Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.

Best time to call between Denver and Tokyo

With a +15h offset there is no overlap inside a normal 9 AM – 5 PM day. Tokyo opens at 9:00 AM JST, which is 12:00 AM in Denver, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

Denver and Tokyo have no shared working hours because of the +15h gap. Teams need to alternate early starts or rely on asynchronous handovers.

Denver is 15 hours ahead of Tokyo (MDT UTC-06:00 → JST UTC+09:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

Denver

☀ Currently in DST

Standard: UTC-07:00 · DST: UTC-06:00

Clocks fall back on Sun, Nov 1, 2026

Tokyo

Does not observe DST

Learn More About Time

Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between Denver and Tokyo?

Denver (MDT, UTC-06:00) is 15 hours ahead of Tokyo (JST, UTC+09:00). The gap is currently +15h.

How do I convert Denver time to Tokyo time?

Add +15h to Denver local time. For example, 9:00 AM in Denver is 12:00 AM in Tokyo (next day).

What time is it in Tokyo right now?

Tokyo uses JST at UTC+09:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +15h offset from Denver.

What is the best time to call Tokyo from Denver?

There is no shared working-hours window because of the +15h gap. The closest option is 1:00 PM in Denver, which is 4:00 AM in Tokyo.

Which is ahead, Denver or Tokyo?

Denver is 15 hours ahead of Tokyo. When it is 12:00 PM in Denver it is 3:00 AM in Tokyo.

Do Denver and Tokyo use different time zones?

Denver (USA) uses MDT at UTC-06:00, while Tokyo (Japan) uses JST at UTC+09:00. The IANA identifiers are America/Denver and Asia/Tokyo.

Does daylight saving time affect the Denver–Tokyo difference?

Yes at the moment: Denver is on daylight saving time and Tokyo is not, so the +15h gap shifts by an hour when exactly one of them changes clocks.

Which other cities share Denver's time zone?

MDT also covers Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson and 2 more.

Which countries use MDT, Denver's zone?

MDT is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).

Is there a day difference between Denver and Tokyo?

Sometimes. The +15h gap is large enough that 8:00 PM or later in Denver already falls on the next day in Tokyo.

What is the time difference between Denver and Tokyo?

Tokyo is +15h from Denver.

What timezone is Denver in?

Denver operates on Mountain Time (MST/MDT), 2 hours behind New York. As a tech and aerospace hub, Denver bridges West Coast and Central US business hours.

What timezone is Tokyo in?

Tokyo operates on Japan Standard Time (JST), which is 14 hours ahead of New York. As Asia's largest financial hub, Tokyo trading hours are crucial for global markets.

What are the business hours in Denver?

Standard business hours in Denver are 8:00 AM - 5:00 PM MST.

What are the business hours in Tokyo?

Standard business hours in Tokyo are 9:00 AM - 6:00 PM JST.

What is the best time to schedule a call between Denver and Tokyo?

The best overlap for a call is when both cities are in business hours. Denver works 8:00 AM - 5:00 PM MST and Tokyo works 9:00 AM - 6:00 PM JST (+15h difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Denver and Tokyo?

Denver uses USD ($) while Tokyo uses JPY (¥). Check current exchange rates when planning travel or business between these cities.

How do Denver and Tokyo compare in size?

Denver has a population of approximately 715,000 (metro: 2.9 million), while Tokyo has approximately 14 million (metro: 37.4 million).

What are the major landmarks in Denver and Tokyo?

Denver is known for Red Rocks Amphitheatre, Denver Art Museum, Union Station. Tokyo is famous for Tokyo Tower, Shibuya Crossing, Senso-ji Temple.

Do Denver and Tokyo have stock exchanges?

Yes. Denver has the N/A (Uses NYSE/NASDAQ) and Tokyo has the TSE (Tokyo Stock Exchange). The +15h time difference affects trading hour overlaps between these exchanges.

Which countries use MST (Mountain Standard Time)?

MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).

Does MST observe daylight saving time?

Yes, MST switches to MDT during summer months.

What are some interesting facts about MST?

Arizona does not observe daylight saving time, staying on MST year-round. The Navajo Nation in Arizona does observe DST, unlike the rest of the state.