What is the time difference between AEST and MST?

Mountain Standard Time (MST) is 17 hours behind Australian Eastern Standard Time (AEST). AEST uses a UTC offset of UTC+11, while MST uses UTC-6. For example, when it's 9:00 AM in AEST, it's 4:00 PM in MST. Note that this difference may shift by one hour during daylight saving time transitions if the two zones change on different dates. Use the conversion table above to see the exact time for each hour of the day.

How do I convert AEST to MST?

To convert AEST to MST, subtract 17 hours from the AEST time. For example, 9:00 AM AEST is 4:00 PM MST, and 5:00 PM AEST is 12:00 AM MST. Keep in mind that during daylight saving time transitions, the offset between these timezones may temporarily change by one hour. You can also use the interactive converter above for quick, accurate results.

What time is it in MST when it's noon in AEST?

When it's 12:00 PM (noon) in AEST, it's 7:00 PM in MST. This is because MST is 17 hours behind AEST. Similarly, when it's 6:00 PM in AEST, it's 1:00 AM in MST. During daylight saving time transitions, these times may shift by one hour, so always verify the current offset. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours behind is MST from AEST?

MST is 17 hours behind AEST. This means when it's 9:00 AM in AEST, it's 4:00 PM in MST, and when it's midnight in AEST, it's 7:00 AM in MST. The exact difference can vary by one hour during daylight saving time transitions. The conversion table above provides a complete hour-by-hour mapping.

Is MST ahead or behind AEST?

MST is behind AEST by 17 hours. Clocks in MST show an earlier time than AEST, meaning the day starts later in MST relative to AEST. For example, when it's noon in AEST, it's still 7:00 PM in MST. This gap may change by one hour during DST transitions.

Does AEST observe daylight saving time?

Yes, Australian Eastern Standard Time observes daylight saving time. During DST, the abbreviation changes to AEDT and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard AEST time. This means the UTC offset for AEST shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your AEST to MST conversions.

Does MST observe daylight saving time?

Yes, Mountain Standard Time observes daylight saving time. During DST, the abbreviation changes to MDT and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard MST time. This means the UTC offset for MST shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your AEST to MST conversions.

What is the best time to call from AEST to MST?

The best time for a call between AEST and MST is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in MST during their work day, call between 2:00 AM and 10:00 AM your AEST time. Avoid calling too early or late, as the 17 hours difference means your evening could be their early morning. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

When does daylight saving time change in AEST?

Daylight saving time transitions vary by year and region. Australian Eastern Standard Time observes DST, which typically shifts clocks forward by one hour in spring ("spring forward") and back in fall ("fall back"). During these transition periods, the time difference between AEST and MST may temporarily change by one hour, which can cause confusion for scheduled meetings or calls. It's important to double-check your conversions around transition dates, especially if the two timezones switch on different dates. Check our DST change calendar for exact transition dates in the current year.

Do AEST and MST ever have the same time?

No, AEST and MST are always 17 hours apart and never display the same clock time simultaneously. Both timezones observe DST and typically transition around the same period, so the standard difference remains consistent throughout the year. The 17 hours offset is determined by their fixed positions relative to the Prime Meridian (UTC). You can always rely on this consistent difference when planning across these timezones.

AEST to MST Converter

Convert Australian Eastern Standard Time to Mountain Standard Time. See the hour-by-hour conversion table below.

Upcoming DST Change

Australian Eastern Time (AEDT) will fall back on April 5. Clocks will shift by 1 hour (AEDT → AEST).

View all DST changes

Timezone Details

Australian Eastern Standard Time

4:08 AM

Friday, April 3, 2026

AEDT (UTC+11:00)

Mountain Standard Time

11:08 AM

Thursday, April 2, 2026

MDT (UTC-06:00)

Difference: -17 hours

AEDT DST: Yes (AEDT)

MDT DST: Yes (MDT)

24-Hour Overview

AEDT — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

MDT — 24-hour overview

7a7a

10a10a

11a

12p

1p1p

4p4p

7p7p

10p10p

11p

12a

1a1a

4a4a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

MST to AEST GMT to AEST AEST to GMT IST to AEST AEST to IST MST to GMT GMT to MST EST to AEST AEST to EST

Cities in These Timezones

AEST Cities

Sydney Canberra

MST Cities

Denver

More Tools

Compare AEST & MST Plan a Meeting (AEST & MST)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Australian Eastern Standard Time on Wikipedia Mountain Standard Time on Wikipedia IANA Time Zone Database