MST to AWST
+15hMST
MSTSOURCEAWST
AWSTGreen rows indicate typical business hours (9 AM - 5 PM)
MST and AWST on the World Map
The map below highlights the MST (Mountain Standard Time) and AWST (Australian Western Standard 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.
AWST – Australian Western Standard Time
UTC+08:00Australian Western Standard Time (AWST) is the time zone for Western Australia, 8 hours ahead of UTC.
- •Western Australia does not observe daylight saving time.
- •Perth is the most isolated major city in the world.
- •AWST is the same offset as China Standard Time and Singapore Time.
Comparing Time Zones: MST and AWST
MST runs on Mountain Standard Time (MST) at UTC-07:00. AWST runs on Australian Western Standard Time (AWST) at UTC+08:00. That puts MST 15 hours ahead of AWST — a difference of +15h at the current offsets.
In practice, when it is 9:00 AM in MST it is 12:00 AM in AWST on the next day. Midnight in MST is 3:00 PM in AWST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
MST to AWST time conversion table
| MST (MST) | AWST (AWST) | 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 MST to AWST time
- Scheduling a call from MST to AWST: a 10:00 AM start in MST lands at 1:00 AM in AWST the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +15h gap: MST and AWST 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 AWST is 12:00 AM in MST.
- Keeping family and friends in sync: knowing that 8:00 PM in MST is 11:00 AM in AWST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM MST" 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 MST takes the early slot, the next week AWST 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 AWST (Australian Western Standard Time)
Australian Western Standard Time (AWST) is used in Western Australia. WA does not observe daylight saving time, having rejected it in multiple referendums. Perth is the most remote major city in the world.
Best time to call between MST and AWST
With a +15h offset there is no overlap inside a normal 9 AM – 5 PM day. AWST opens at 9:00 AM AWST, which is 12:00 AM in MST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
MST and AWST have no shared working hours because of the +15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
MST is 15 hours ahead of AWST (MST UTC-07:00 → AWST UTC+08:00). 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
AWST
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:
Frequently Asked Questions
What is the time difference between MST and AWST?
MST (MST, UTC-07:00) is 15 hours ahead of AWST (AWST, UTC+08:00). The gap is currently +15h.
How do I convert MST time to AWST time?
Add +15h to MST local time. For example, 9:00 AM in MST is 12:00 AM in AWST (next day).
What time is it in AWST right now?
AWST uses AWST at UTC+08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +15h offset from MST.
What is the best time to call AWST from MST?
There is no shared working-hours window because of the +15h gap. The closest option is 1:00 PM in MST, which is 4:00 AM in AWST.
Which is ahead, MST or AWST?
MST is 15 hours ahead of AWST. When it is 12:00 PM in MST it is 3:00 AM in AWST.
Does daylight saving time affect the MST–AWST difference?
Neither zone observes daylight saving time, so the +15h offset between MST and AWST 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 AWST?
Sometimes. The +15h gap is large enough that 8:00 PM or later in MST already falls on the next day in AWST.
What is the time difference between MST and AWST?
AWST is +15h from MST.
What timezone is MST in?
MST operates on its local timezone.
What timezone is AWST in?
AWST 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 AWST timezone?
Major cities in the AWST timezone include Perth, Mandurah, Bunbury, Geraldton.
What is the UTC offset for AWST?
Australian Western Standard Time (AWST) is at UTC+08:00.
What should I know about the AWST timezone?
Western Australia does not observe daylight saving time. Perth is the most isolated major city in the world.
When is it midnight in MST, what time is it in AWST?
When it is 12:00 AM (midnight) in MST (MST), it is +15h later in AWST (AWST).
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See every conversion from MST →·See every conversion from AWST →