HST to MT Time Converter
MT is 4 hours ahead of HST. HST is UTC-10:00, and The US Mountain states are currently on MDT (UTC-6:00).
Best Time to Call Between HST and MT
Both zones are inside normal business hours between 9:00 AM and 1:00 PM HST — that's 1:00 PM to 5:00 PM MT. That's a 4-hour window.
both at work HST only MT only neither — hours along the strip are HST.
Common Times Converted
HST on the left, MT on the right.
HST to MT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| HST | MT | Working hours |
|---|---|---|
| 12:00 AM | 4:00 AM | — |
| 1:00 AM | 5:00 AM | — |
| 2:00 AM | 6:00 AM | — |
| 3:00 AM | 7:00 AM | — |
| 4:00 AM | 8:00 AM | — |
| 5:00 AM | 9:00 AM | MT only |
| 6:00 AM | 10:00 AM | MT only |
| 7:00 AM | 11:00 AM | MT only |
| 8:00 AM | 12:00 PM | MT only |
| 9:00 AM | 1:00 PM | Both zones |
| 10:00 AM | 2:00 PM | Both zones |
| 11:00 AM | 3:00 PM | Both zones |
| 12:00 PM | 4:00 PM | Both zones |
| 1:00 PM | 5:00 PM | HST only |
| 2:00 PM | 6:00 PM | HST only |
| 3:00 PM | 7:00 PM | HST only |
| 4:00 PM | 8:00 PM | HST only |
| 5:00 PM | 9:00 PM | — |
| 6:00 PM | 10:00 PM | — |
| 7:00 PM | 11:00 PM | — |
| 8:00 PM | 12:00 AM next day | — |
| 9:00 PM | 1:00 AM next day | — |
| 10:00 PM | 2:00 AM next day | — |
| 11:00 PM | 3:00 AM next day | — |
What HST and MT Actually Are
HST — Hawaii Standard Time
Honolulu and the rest of Hawaii. Standing at UTC-10:00 as written, and the region does not change its clocks, so that offset holds all year. Hawaii does not observe daylight saving, so this offset holds all year.
Hawaii dropped daylight saving in 1967 and never resumed it. Being close to the equator, its daylight barely varies across the year, so there is little to gain.
MT — Mountain Time
Denver, Salt Lake City, Calgary, Edmonton — and Phoenix, which does not change its clocks. 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.
Mountain Time contains the most conspicuous daylight saving exception in North America: Arizona, which has opted out since 1968.
What This Means in Practice
This gap is not fixed
MT changes its clocks and HST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, November 1, 2026 unless someone resets it.
Major Cities in Each Zone
Cities on HST
Cities on MT
Frequently Asked Questions
What is the time difference between HST and MT?
MT is 4 hours ahead of HST. That is the live figure. Taken strictly as written, the gap between HST and MT is 3 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM HST in MT?
9:00 AM HST is 1:00 PM MT.
What are the best hours to schedule a call between HST and MT?
Between 9:00 AM and 1:00 PM HST, which is 1:00 PM to 5:00 PM MT. Both sides are inside normal business hours through that window.
Does the difference between HST and MT change during the year?
Yes. MT observes daylight saving and HST does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.
Does HST always mean Hawaii Standard Time?
Hawaii does not observe daylight saving, so this offset holds all year.