MST to AEDT
+18hMST
MSTSOURCEAEDT
AEDTGreen rows indicate typical business hours (9 AM - 5 PM)
MST and AEDT on the World Map
The map below highlights the MST (Mountain Standard Time) and AEDT (Australian Eastern Daylight Time) timezone regions across the globe.
MST – Mountain Standard Time
UTC-07:00Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.
- •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.
AEDT – Australian Eastern Daylight Time
UTC+11:00Australian Eastern Daylight Time (AEDT, UTC+11:00) is the daylight saving period in south-eastern Australia, from October to April.
- •AEDT runs from the first Sunday in October to the first Sunday in April.
- •AEDT is one hour ahead of Australian Eastern Standard Time (AEST).
- •Queensland does not observe daylight saving, so Brisbane stays on AEST.
- •During AEDT, Sydney is 16 hours ahead of New York and 11 hours ahead of UTC.
MST vs AEDT: Offsets, DST and Best Call Times
MST runs on Mountain Standard Time (MST) at UTC-07:00. AEDT runs on Australian Eastern Daylight Time (AEDT) at UTC+11:00. That puts MST 18 hours ahead of AEDT — a difference of +18h at the current offsets.
In practice, when it is 9:00 AM in MST it is 3:00 AM in AEDT on the next day. Midnight in MST is 6:00 PM in AEDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
MST to AEDT time conversion table
| MST (MST) | AEDT (AEDT) | Day |
|---|---|---|
| 12:00 AM | 6:00 PM | same day |
| 6:00 AM | 12:00 AM | next day |
| 7:00 AM | 1:00 AM | next day |
| 8:00 AM | 2:00 AM | next day |
| 9:00 AM | 3:00 AM | next day |
| 12:00 PM | 6:00 AM | next day |
| 3:00 PM | 9:00 AM | next day |
| 5:00 PM | 11:00 AM | next day |
| 6:00 PM | 12:00 PM | next day |
| 9:00 PM | 3:00 PM | next day |
Why people convert MST to AEDT time
- Scheduling a call from MST to AEDT: a 10:00 AM start in MST lands at 4:00 AM in AEDT the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +18h gap: MST and AEDT 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 AEDT is 3:00 AM in MST.
- Coordinating a MST-based team with AEDT 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 MST" is unambiguous; "3 PM" across a +18h gap is not.
- With a +18h gap there is no shared 9-to-5 window, so alternate the early start: one week MST takes the early slot, the next week AEDT does.
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 AEDT (Australian Eastern Daylight Time)
Australian Eastern Daylight Time (AEDT) is the daylight saving period in south-eastern Australia, one hour ahead of Australian Eastern Standard Time (AEST, UTC+10:00). Because Australia is in the southern hemisphere, AEDT runs through the summer — from the first Sunday in October to the first Sunday in April — which is almost exactly the reverse of the European and North American schedules. New South Wales, Victoria, Tasmania and the Australian Capital Territory observe it; Queensland and the Northern Territory do not, so Brisbane stays on AEST year round while Sydney moves to AEDT. During AEDT, Sydney is 11 hours ahead of UTC and 16 hours ahead of New York.
Best time to call between MST and AEDT
With a +18h offset there is no overlap inside a normal 9 AM – 5 PM day. AEDT opens at 9:00 AM AEDT, which is 3:00 AM in MST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
MST and AEDT have no shared working hours because of the +18h gap. Teams need to alternate early starts or rely on asynchronous handovers.
MST is 18 hours ahead of AEDT (MST UTC-07:00 → AEDT UTC+11:00). 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
MST
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
AEDT
❄ Currently in Standard Time
Standard: UTC+10:00 · DST: UTC+11:00
Clocks spring forward on Sat, Oct 3, 2026
⚠ These locations are currently in different DST states, so the time difference may change when clocks adjust.
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between MST and AEDT?
MST (MST, UTC-07:00) is 18 hours ahead of AEDT (AEDT, UTC+11:00). The gap is currently +18h.
How do I convert MST time to AEDT time?
Add +18h to MST local time. For example, 9:00 AM in MST is 3:00 AM in AEDT (next day).
What time is it in AEDT right now?
AEDT uses AEDT at UTC+11:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +18h offset from MST.
What is the best time to call AEDT from MST?
There is no shared working-hours window because of the +18h gap. The closest option is 1:00 PM in MST, which is 7:00 AM in AEDT.
Which is ahead, MST or AEDT?
MST is 18 hours ahead of AEDT. When it is 12:00 PM in MST it is 6:00 AM in AEDT.
Does daylight saving time affect the MST–AEDT difference?
Neither zone observes daylight saving time, so the +18h offset between MST and AEDT is fixed all year.
Which other cities share MST's time zone?
MST also covers Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson and 2 more.
Which countries use MST, MST's zone?
MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).
Is there a day difference between MST and AEDT?
Sometimes. The +18h gap is large enough that 8:00 PM or later in MST already falls on the next day in AEDT.
What is the time difference between MST and AEDT?
AEDT is +18h from MST.
What timezone is MST in?
MST operates on its local timezone.
What timezone is AEDT in?
AEDT operates on its local timezone.
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.
Which cities are in the AEDT timezone?
Major cities in the AEDT timezone include Sydney, Melbourne, Canberra, Hobart, Newcastle.
What is the UTC offset for AEDT?
Australian Eastern Daylight Time (AEDT) is at UTC+11:00. During daylight saving time, it shifts to AEDT.
What should I know about the AEDT timezone?
AEDT runs from the first Sunday in October to the first Sunday in April. AEDT is one hour ahead of Australian Eastern Standard Time (AEST).
When is it midnight in MST, what time is it in AEDT?
When it is 12:00 AM (midnight) in MST (MST), it is +18h later in AEDT (AEDT).
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See every conversion from MST →·See every conversion from AEDT →