MST to ACST Converter

Standard business hours (9 AM–5 PM, Mon–Fri) in Mountain Time and Australian Central Time don't overlap on the same weekday. Australian Central Time is 16 hours ahead of Mountain Time.

With some flexibility, there’s a workable window outside standard hours:

• 4 PM–8 PM in Mountain Time (7 AM–11 AM the next day in Australian Central Time) — suggest 6:00 PM Mountain Time (9:30 AM Australian Central Time).

This means an early start or late finish for one side, but it’s a reasonable slot for a one-off meeting.

Mountain Time is also known as MST, or MDT. To call United States, dial +1.

Australian Central Time is also known as ACST, or ACDT. To call Australia, dial +61.

Australian Central Time is approximately 9,000 miles west of Mountain Time.

Both zones observe daylight saving time, but they transition on different dates.

Mountain Time: next transition on Sunday, November 1, 2026.

Australian Central Time: next transition on Sunday, October 4, 2026.

Mountain Time and Australian Central Time are in opposite hemispheres, so their clocks change in opposite directions about six months apart — one springs forward while the other falls back. The offset between them therefore shifts twice a year and can swing by up to two hours across the seasons, more than a typical same-hemisphere pair. Recurring meetings will need re-checking after each transition.

See the daylight saving time page for transition dates across every time zone.