MST to Sydney
+17hMST
MSTSOURCESydney
AESTGreen rows indicate typical business hours (9 AM - 5 PM)
MST and AEST on the World Map
The map below highlights the MST (Mountain Standard Time) and AEST (Australian Eastern 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.
AEST – Australian Eastern Standard Time
UTC+10:00Australian Eastern Standard Time (AEST) covers eastern Australia, 10 hours ahead of UTC.
- •Queensland does not observe daylight saving time, staying on AEST year-round.
- •Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
- •The Australian Securities Exchange (ASX) operates on AEST/AEDT.
- •AEST is 15 hours ahead of EST during winter.
About Sydney
WikipediaSydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.
Sydney is one of the first major cities to welcome the New Year.
MST vs Sydney: Offsets, DST and Best Call Times
MST runs on Mountain Standard Time (MST) at UTC-07:00. Sydney runs on Australian Eastern Standard Time (AEST) at UTC+10:00. That puts MST 17 hours ahead of Sydney — a difference of +17h at the current offsets.
In practice, when it is 9:00 AM in MST it is 2:00 AM in Sydney on the next day. Midnight in MST is 5:00 PM in Sydney. Neither zone observes daylight saving time, so the offset between them stays constant all year.
MST to Sydney time conversion table
| MST (MST) | Sydney (AEST) | Day |
|---|---|---|
| 12:00 AM | 5:00 PM | same day |
| 6:00 AM | 11:00 PM | same day |
| 7:00 AM | 12:00 AM | next day |
| 8:00 AM | 1:00 AM | next day |
| 9:00 AM | 2:00 AM | next day |
| 12:00 PM | 5:00 AM | next day |
| 3:00 PM | 8:00 AM | next day |
| 5:00 PM | 10:00 AM | next day |
| 6:00 PM | 11:00 AM | next day |
| 9:00 PM | 2:00 PM | next day |
Why people convert MST to Sydney time
- Scheduling a call from MST to Sydney: a 10:00 AM start in MST lands at 3:00 AM in Sydney the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +17h gap: MST and Sydney 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 Sydney is 2:00 AM in MST.
- Coordinating a MST-based team with Sydney 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 +17h gap is not.
- With a +17h gap there is no shared 9-to-5 window, so alternate the early start: one week MST takes the early slot, the next week Sydney does.
- Sydney: Clocks spring forward on Sat, Oct 3, 2026. Any meeting series spanning that date will shift by an hour in local time.
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 AEST (Australian Eastern Standard Time)
Australian Eastern Standard Time (AEST) is used in the eastern states of Australia including New South Wales, Victoria, Queensland, Tasmania, and the ACT. During summer (October to April), NSW, VIC, TAS, and ACT switch to Australian Eastern Daylight Time (AEDT, UTC+11:00), while Queensland remains on AEST year-round.
Best time to call between MST and Sydney
With a +17h offset there is no overlap inside a normal 9 AM – 5 PM day. Sydney opens at 9:00 AM AEST, which is 2:00 AM in MST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
MST and Sydney have no shared working hours because of the +17h gap. Teams need to alternate early starts or rely on asynchronous handovers.
MST is 17 hours ahead of Sydney (MST UTC-07:00 → AEST UTC+10:00). 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
Sydney
❄ 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 Sydney?
MST (MST, UTC-07:00) is 17 hours ahead of Sydney (AEST, UTC+10:00). The gap is currently +17h.
How do I convert MST time to Sydney time?
Add +17h to MST local time. For example, 9:00 AM in MST is 2:00 AM in Sydney (next day).
What time is it in Sydney right now?
Sydney uses AEST at UTC+10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +17h offset from MST.
What is the best time to call Sydney from MST?
There is no shared working-hours window because of the +17h gap. The closest option is 1:00 PM in MST, which is 6:00 AM in Sydney.
Which is ahead, MST or Sydney?
MST is 17 hours ahead of Sydney. When it is 12:00 PM in MST it is 5:00 AM in Sydney.
Do MST and Sydney use different time zones?
MST uses MST at UTC-07:00, while Sydney (Australia) uses AEST at UTC+10:00. The IANA identifiers are America/Denver and Australia/Sydney.
Does daylight saving time affect the MST–Sydney difference?
Neither zone observes daylight saving time, so the +17h offset between MST and Sydney 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 Sydney?
Sometimes. The +17h gap is large enough that 8:00 PM or later in MST already falls on the next day in Sydney.
What is the time difference between MST and Sydney?
Sydney is +17h from MST.
What timezone is MST in?
MST operates on its local timezone.
What timezone is Sydney in?
Sydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.
What are the business hours in Sydney?
Standard business hours in Sydney are 9:00 AM - 5:00 PM AEST.
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 AEST timezone?
Major cities in the AEST timezone include Sydney, Melbourne, Brisbane, Canberra, Hobart, Gold Coast.
What is the UTC offset for AEST?
Australian Eastern Standard Time (AEST) is at UTC+10:00. During daylight saving time, it shifts to AEDT.
What should I know about the AEST timezone?
Queensland does not observe daylight saving time, staying on AEST year-round. Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
When is it midnight in MST, what time is it in Sydney?
When it is 12:00 AM (midnight) in MST (MST), it is +17h later in Sydney (AEST).
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