MST to AEDT Time Converter
AEDT is 17 hours ahead of MST. The US Mountain states are currently on MDT (UTC-6:00), and AEDT is UTC+11:00.
Best Time to Call Between MST and AEDT
Both zones are inside normal business hours between 4:00 PM and 5:00 PM MST — that's 9:00 AM to 10:00 AM AEDT. That's a 1-hour window.
both at work MST only AEDT only neither — hours along the strip are MST.
Common Times Converted
MST on the left, AEDT on the right.
MST to AEDT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| MST | AEDT | Working hours |
|---|---|---|
| 12:00 AM | 5:00 PM | — |
| 1:00 AM | 6:00 PM | — |
| 2:00 AM | 7:00 PM | — |
| 3:00 AM | 8:00 PM | — |
| 4:00 AM | 9:00 PM | — |
| 5:00 AM | 10:00 PM | — |
| 6:00 AM | 11:00 PM | — |
| 7:00 AM | 12:00 AM next day | — |
| 8:00 AM | 1:00 AM next day | — |
| 9:00 AM | 2:00 AM next day | MST only |
| 10:00 AM | 3:00 AM next day | MST only |
| 11:00 AM | 4:00 AM next day | MST only |
| 12:00 PM | 5:00 AM next day | MST only |
| 1:00 PM | 6:00 AM next day | MST only |
| 2:00 PM | 7:00 AM next day | MST only |
| 3:00 PM | 8:00 AM next day | MST only |
| 4:00 PM | 9:00 AM next day | Both zones |
| 5:00 PM | 10:00 AM next day | AEDT only |
| 6:00 PM | 11:00 AM next day | AEDT only |
| 7:00 PM | 12:00 PM next day | AEDT only |
| 8:00 PM | 1:00 PM next day | AEDT only |
| 9:00 PM | 2:00 PM next day | AEDT only |
| 10:00 PM | 3:00 PM next day | AEDT only |
| 11:00 PM | 4:00 PM next day | AEDT only |
What MST and AEDT Actually Are
MST — Mountain Standard Time
Denver, Salt Lake City, Calgary — and Phoenix year-round. Standing at UTC-7:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to MST. Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.
Arizona has stayed on MST year-round since 1968 — the Navajo Nation within it does observe daylight saving, making the state a patchwork.
AEDT — Australian Eastern Daylight Time
Sydney, Melbourne, Canberra, Hobart from October to April. Standing at UTC+11:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, April 4, 2027, to AEST. Brisbane and the rest of Queensland stay on AEST year-round, so they fall an hour behind Sydney each summer.
AEDT is the southern summer half of Eastern Australia, running roughly October to April — the opposite half of the year from northern hemisphere daylight time.
What This Means in Practice
The date changes mid-working-day
For 8 of the eight hours in a normal MST working day, the equivalent AEDT time falls on a different calendar date. Anything scheduled in that stretch needs the date checked as well as the time, or a Tuesday call quietly becomes a Wednesday one at the other end.
Both sides change clocks, on different dates
Both regions observe daylight saving but do not switch on the same day, so for a week or two each spring and fall the gap between them is an hour different from the rest of the year. Those short windows are where recurring invitations quietly break.
Nearly opposite sides of the clock
At 17 hours apart, one side's morning is the other side's night. Handing work over at the end of a shift usually beats trying to get both parties in the same call.
Major Cities in Each Zone
Cities on MST
Cities on AEDT
Frequently Asked Questions
What is the time difference between MST and AEDT?
AEDT is 17 hours ahead of MST. That is the live figure. Taken strictly as written, the gap between MST and AEDT is 18 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM MST in AEDT?
9:00 AM MST is 2:00 AM the next day AEDT.
What are the best hours to schedule a call between MST and AEDT?
Between 4:00 PM and 5:00 PM MST, which is 9:00 AM to 10:00 AM AEDT. Both sides are inside normal business hours through that window.
Does the difference between MST and AEDT change during the year?
Yes. Both regions observe daylight saving, and they do not switch on the same dates, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.
Does MST always mean Mountain Standard Time?
Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.
Does AEDT always mean Australian Eastern Daylight Time?
Brisbane and the rest of Queensland stay on AEST year-round, so they fall an hour behind Sydney each summer.