MDT to MST Converter

Category: Time Zone Converters

- July 03, 2025

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Mountain Daylight Time (MDT)

UTC-6 • Denver, Calgary, Salt Lake City

Conversion Settings

Configure your timezone conversion preferences

Auto Convert

Daylight Saving Aware

Show UTC Offset

Show Seconds

Mountain Standard Time (MST)

UTC-7 • Phoenix, Tucson, Flagstaff

--:--:--

Select a time to convert

Time Difference: --

UTC Offset (MDT/MST): -6

UTC Offset (Arizona MST): -7

DST Status: --

MDT/MST Time: --

Arizona MST Time: --

Time Format:

Current Mountain Time: --:--:--

Current Arizona Time: --:--:--

🌍 Mountain Time switches between MDT (UTC-6) and MST (UTC-7). Arizona stays on MST year-round (UTC-7).

MDT to MST Conversion Guide

What is MDT to MST Conversion?

MDT to MST conversion helps you understand the relationship between Mountain Daylight Time and Mountain Standard Time. Most of the Mountain Time Zone switches between MDT (UTC-6) during daylight saving time (March-November) and MST (UTC-7) during standard time (November-March). However, most of Arizona stays on MST year-round and doesn't observe daylight saving time, creating a unique situation where Arizona can be either the same time as or 1 hour behind other Mountain Time Zone locations depending on the season.

Time Zone Information

Mountain Daylight Time (MDT): UTC-6, used in most Mountain Time Zone areas during daylight saving time from second Sunday in March to first Sunday in November.

Mountain Standard Time (MST): UTC-7, used during standard time from first Sunday in November to second Sunday in March.

Arizona Standard Time: UTC-7 year-round, as most of Arizona doesn't observe daylight saving time.

Time Difference: MDT is 1 hour ahead of MST; Arizona MST matches other Mountain areas only in winter.

Daylight Saving Time Impact

Standard Mountain Time: MDT observed from second Sunday in March to first Sunday in November

Arizona Exception: Most of Arizona stays on MST year-round and doesn't change clocks

Seasonal Difference: Arizona is same time as Mountain zones in winter, 1 hour behind in summer

Navajo Nation: Parts of Arizona (Navajo Nation) do observe daylight saving time like other Mountain areas

Common Conversion Examples

Summer Time (MDT vs Arizona MST)

MDT 12:00 PM → Arizona MST 11:00 AM

MDT 6:00 PM → Arizona MST 5:00 PM

Summer: Arizona is 1 hour behind Mountain Daylight areas

Winter Time (MST vs Arizona MST)

MST 12:00 PM → Arizona MST 12:00 PM

MST 6:00 PM → Arizona MST 6:00 PM

Winter: Arizona matches other Mountain Standard areas

Business Coordination

Denver MDT 9:00 AM → Phoenix MST 8:00 AM

Denver MST 9:00 AM → Phoenix MST 9:00 AM

Important for Denver-Phoenix business meetings

Travel Planning

Salt Lake MDT 3:00 PM → Arizona MST 2:00 PM

Salt Lake MST 3:00 PM → Arizona MST 3:00 PM

Critical for flight schedules and appointments

Conversion Tips & Best Practices

• Most Mountain Time Zone areas switch between MDT (summer) and MST (winter)

• Arizona (except Navajo Nation) stays on MST year-round - no daylight saving time

• In summer: Arizona is 1 hour behind MDT areas; in winter: times match

• When scheduling across Mountain zones, always check if Arizona observes DST

• Hawaii and most of Arizona are the only US states/territories that don't observe DST

• Mountain Time Zone covers parts of 13 US states and 5 Canadian provinces/territories

Convert Between MDT and Arizona MST

If you've ever needed to figure out what time it is in Arizona compared to Denver or Salt Lake City, you're not alone. The trick is that Arizona doesn’t observe daylight saving time, while the rest of the Mountain Time zone does. That’s where this time conversion calculator comes in. Whether you're planning a call, a trip, or managing remote work, this tool helps you line things up without confusion.

MDT (UTC-6) Used in summer months	MST (Arizona - UTC-7) Used year-round
🇺🇸 United States (parts of CO, NM, UT, WY, MT, ID, ND, SD, TX) 🇨🇦 Canada (parts of Alberta, British Columbia, Northwest Territories, Nunavut) 🇲🇽 Mexico (Chihuahua)	🇺🇸 United States (Arizona, excluding Navajo Nation)

Why this tool is useful no matter the season

Mountain Daylight Time (MDT) and Mountain Standard Time (MST) are just one hour apart, but when that difference kicks in depends entirely on the calendar. Most of the Mountain Time region changes their clocks in March and November. Arizona doesn’t. That throws a wrench into meetings, flights, or scheduling across these areas.

This calculator helps bridge that gap. It tells you exactly what the local time will be in Arizona when it’s a certain time in Colorado or vice versa. The goal is simple: no surprises on your calendar.

Set it up once, get answers fast

Pick your input timezone

The calculator defaults to MDT, meaning it assumes you’re starting in a daylight saving region. But you can switch to Arizona MST from the dropdown menu if that’s your starting point. You can also swap back and forth with the ⇄ button.

Select your date and time

Choose the day and time you want to convert. This can be in the past or future, and the tool will automatically detect whether daylight saving time is in effect. You can use the “Now” button if you want to see the current time difference instantly.

Get your answer

Click "Convert Time" and the tool displays the result immediately. If you’ve enabled auto-convert (which is on by default), it will do this the moment you change any field. The answer includes the full date, time, and whether it’s MDT or MST.

Extra settings to make things more accurate

Auto Convert

Leave this checked if you want the tool to calculate results instantly as you type. Uncheck it if you prefer to manually trigger conversions.

Daylight Saving Aware

This is what makes the tool so precise. With this setting on, it checks if the date you chose is in the daylight saving period. If it’s off, it assumes standard time for everything.

Show UTC Offset

Turn this on if you need to see the raw UTC offset numbers (like -6:00 or -7:00). It’s handy if you're comparing to timezones outside the US.

Show Seconds

For more granular work, like tracking server logs or broadcasts, you can keep this checked to show full timestamps with seconds included.

Toggle between 12-hour and 24-hour formats

Hit the “12 Hour” button to switch formats. Once clicked, it becomes “24 Hour” and updates the display immediately. Handy if you’re used to military or European time notation.

Quick use case: Working across Colorado and Arizona

Say you're based in Colorado and need to schedule a video call with someone in Arizona. It’s June, so Colorado is on MDT (UTC-6), while Arizona is on MST (UTC-7). That means if your meeting is at 2:00 PM in Denver, it’s 1:00 PM in Phoenix. This calculator shows that difference right away, so you don’t have to guess. Even better, it adjusts for DST automatically so when November comes, you’ll see that the two states are back in sync.

Make timezone math something you never worry about again

The whole point of this tool is to remove the mental gymnastics. Whether it’s for coordinating family across states, managing teams in multiple locations, or just making sure your flight lands when you think it will, this calculator has your back. Once you use it, you’ll stop second-guessing your calendar, and that’s time well saved.

MDT to MST Converter

Mountain Daylight Time (MDT)

Conversion Settings

Mountain Standard Time (MST)

MDT to MST Conversion Guide

What is MDT to MST Conversion?

Time Zone Information

Daylight Saving Time Impact

Common Conversion Examples

Conversion Tips & Best Practices

Convert Between MDT and Arizona MST

Why this tool is useful no matter the season

Set it up once, get answers fast

Pick your input timezone

Select your date and time

Get your answer

Extra settings to make things more accurate

Auto Convert

Daylight Saving Aware

Show UTC Offset

Show Seconds

Toggle between 12-hour and 24-hour formats

Quick use case: Working across Colorado and Arizona

Make timezone math something you never worry about again

Time Zone Converters:

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