Convert ACDT to MST
MST is 17 hours 30 minutes behind ACDT. ACDT is UTC+10:30 and MST is UTC−7.
Right now: ACDT · MST
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between ACDT and MST. Someone has to take an early or late call — or use asynchronous communication instead.
| ACDT | MST | Suitable? |
|---|---|---|
| 9:00 AM | 3:30 PM (previous day) | outside 9–5 |
| 10:00 AM | 4:30 PM (previous day) | outside 9–5 |
| 11:00 AM | 5:30 PM (previous day) | outside 9–5 |
| 12:00 PM | 6:30 PM (previous day) | outside 9–5 |
| 1:00 PM | 7:30 PM (previous day) | outside 9–5 |
| 2:00 PM | 8:30 PM (previous day) | outside 9–5 |
| 3:00 PM | 9:30 PM (previous day) | outside 9–5 |
| 4:00 PM | 10:30 PM (previous day) | outside 9–5 |
| 5:00 PM | 11:30 PM (previous day) | outside 9–5 |
ACDT to MST conversion table
| ACDT | MST |
|---|---|
| 12:00 AM | 6:30 AM (previous day) |
| 1:00 AM | 7:30 AM (previous day) |
| 2:00 AM | 8:30 AM (previous day) |
| 3:00 AM | 9:30 AM (previous day) |
| 4:00 AM | 10:30 AM (previous day) |
| 5:00 AM | 11:30 AM (previous day) |
| 6:00 AM | 12:30 PM (previous day) |
| 7:00 AM | 1:30 PM (previous day) |
| 8:00 AM | 2:30 PM (previous day) |
| 9:00 AM | 3:30 PM (previous day) |
| 10:00 AM | 4:30 PM (previous day) |
| 11:00 AM | 5:30 PM (previous day) |
| 12:00 PM | 6:30 PM (previous day) |
| 1:00 PM | 7:30 PM (previous day) |
| 2:00 PM | 8:30 PM (previous day) |
| 3:00 PM | 9:30 PM (previous day) |
| 4:00 PM | 10:30 PM (previous day) |
| 5:00 PM | 11:30 PM (previous day) |
| 6:00 PM | 12:30 AM |
| 7:00 PM | 1:30 AM |
| 8:00 PM | 2:30 AM |
| 9:00 PM | 3:30 AM |
| 10:00 PM | 4:30 AM |
| 11:00 PM | 5:30 AM |
About ACDT
Australian Central Daylight Time (ACDT) is UTC+10:30. It is used in Adelaide in summer.
Australian Central Daylight Time is UTC+10:30, what South Australia keeps from October to April. Darwin stays on ACST through the summer, so for those months two cities in the same nominal zone are an hour apart — the only reason to be precise about which of the two abbreviations a meeting invitation carries.
About MST
Mountain Standard Time (MST) is UTC−7. It is used in Denver and Salt Lake City in winter, and Phoenix all year.
Mountain Standard Time is UTC−7. Denver and Salt Lake City use it in winter and switch to MDT in summer; Arizona does not switch at all and stays on MST year-round, which means Phoenix agrees with Denver in winter and with Los Angeles in summer. The Navajo Nation, inside Arizona, does observe daylight saving, so the state contains both. Any scheduling system that maps "Arizona" to "Mountain Time" without the no-DST flag will be an hour out for eight months.
Does this gap change with the seasons?
This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on MST switches to MDT (UTC−6) from March to November. So the 17.5-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.
ACDT does not shift, so the whole change comes from one side. A recurring meeting fixed in ACDT will appear to move by an hour for everyone on the other side, twice a year, without anyone changing anything.
This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.
Frequently asked questions
What time is 9:00 AM ACDT in MST?
9:00 AM ACDT is 3:30 PM MST (previous day).
Is MST ahead of ACDT?
MST is 17 hours 30 minutes behind ACDT.
Which time zone does this use?
ACDT is UTC+10:30 and MST is UTC−7. Both abbreviations denote a single fixed offset, so this conversion never shifts with daylight saving — what changes is which abbreviation a place is using at the time.