AWST to MST
-15hAWST
AWSTSOURCEMST
MSTGreen rows indicate typical business hours (9 AM - 5 PM)
AWST and MST on the World Map
The map below highlights the AWST (Australian Western Standard Time) and MST (Mountain Standard Time) timezone regions across the globe.
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.
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.
Everything You Need to Know About AWST and MST Time
AWST runs on Australian Western Standard Time (AWST) at UTC+08:00. MST runs on Mountain Standard Time (MST) at UTC-07:00. That puts AWST 15 hours behind MST — a difference of -15h at the current offsets.
In practice, when it is 9:00 AM in AWST it is 6:00 PM in MST on the previous day. Midnight in AWST is 9:00 AM in MST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AWST to MST time conversion table
| AWST (AWST) | MST (MST) | Day |
|---|---|---|
| 12:00 AM | 9:00 AM | previous day |
| 6:00 AM | 3:00 PM | previous day |
| 7:00 AM | 4:00 PM | previous day |
| 8:00 AM | 5:00 PM | previous day |
| 9:00 AM | 6:00 PM | previous day |
| 12:00 PM | 9:00 PM | previous day |
| 3:00 PM | 12:00 AM | same day |
| 5:00 PM | 2:00 AM | same day |
| 6:00 PM | 3:00 AM | same day |
| 9:00 PM | 6:00 AM | same day |
Why people convert AWST to MST time
- Scheduling a call from AWST to MST: a 10:00 AM start in AWST lands at 7:00 PM in MST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -15h gap: AWST and MST 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 MST is 6:00 PM in AWST.
- Coordinating a AWST-based team with MST 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 AWST" 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 AWST takes the early slot, the next week MST does.
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.
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).
Best time to call between AWST and MST
With a -15h offset there is no overlap inside a normal 9 AM – 5 PM day. MST opens at 9:00 AM MST, which is 6:00 PM in AWST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
AWST and MST have no shared working hours because of the -15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
AWST is 15 hours behind MST (AWST UTC+08:00 → MST UTC-07:00). 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
AWST
Does not observe DST
MST
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
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 AWST and MST?
AWST (AWST, UTC+08:00) is 15 hours behind MST (MST, UTC-07:00). The gap is currently -15h.
How do I convert AWST time to MST time?
Add -15h to AWST local time. For example, 9:00 AM in AWST is 6:00 PM in MST (previous day).
What time is it in MST right now?
MST uses MST at UTC-07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -15h offset from AWST.
What is the best time to call MST from AWST?
There is no shared working-hours window because of the -15h gap. The closest option is 1:00 PM in AWST, which is 10:00 PM in MST.
Which is behind, AWST or MST?
AWST is 15 hours behind MST. When it is 12:00 PM in AWST it is 9:00 PM in MST.
Does daylight saving time affect the AWST–MST difference?
Neither zone observes daylight saving time, so the -15h offset between AWST and MST is fixed all year.
Which other cities share AWST's time zone?
AWST also covers Perth, Mandurah, Bunbury, Geraldton.
Which countries use AWST, AWST's zone?
AWST is used in Australia (Western Australia).
Is there a day difference between AWST and MST?
Sometimes. The -15h gap is large enough that 8:00 PM or later in AWST already falls on the in MST.
What is the time difference between AWST and MST?
MST is -15h from AWST.
What timezone is AWST in?
AWST operates on its local timezone.
What timezone is MST in?
MST operates on its local timezone.
Which countries use AWST (Australian Western Standard Time)?
AWST is used in Australia (Western Australia).
Does AWST observe daylight saving time?
No, AWST does not observe daylight saving time and remains at UTC+08:00 year-round.
What are some interesting facts about AWST?
Western Australia does not observe daylight saving time. Perth is the most isolated major city in the world.
Which cities are in the MST timezone?
Major cities in the MST timezone include Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson.
What is the UTC offset for MST?
Mountain Standard Time (MST) is at UTC-07:00. During daylight saving time, it shifts to MDT.
What should I know about the MST timezone?
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.
When is it midnight in AWST, what time is it in MST?
When it is 12:00 AM (midnight) in AWST (AWST), it is -15h later in MST (MST).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More AWST time conversions
- awst to perth
- awst to new york
- awst to london
- awst to dubai
- awst to tokyo
- awst to singapore
- awst to sydney
- awst to los angeles
- awst to paris
- awst to delhi
- awst to mumbai
- awst to berlin
- awst to hong kong
- awst to toronto
- awst to kathmandu
- new york to awst
- london to awst
- dubai to awst
- tokyo to awst
- singapore to awst
- sydney to awst
- los angeles to awst
- paris to awst
- delhi to awst
- mumbai to awst
- berlin to awst
- hong kong to awst
- toronto to awst
- kathmandu to awst
See every conversion from AWST →·See every conversion from MST →