MT to HST Time Converter
HST is 4 hours behind MT. The US Mountain states are currently on MDT (UTC-6:00), and HST is UTC-10:00.
Best Time to Call Between MT and HST
Both zones are inside normal business hours between 1:00 PM and 5:00 PM MT — that's 9:00 AM to 1:00 PM HST. That's a 4-hour window.
both at work MT only HST only neither — hours along the strip are MT.
Common Times Converted
MT on the left, HST on the right.
MT to HST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| MT | HST | Working hours |
|---|---|---|
| 12:00 AM | 8:00 PM prev day | — |
| 1:00 AM | 9:00 PM prev day | — |
| 2:00 AM | 10:00 PM prev day | — |
| 3:00 AM | 11:00 PM prev day | — |
| 4:00 AM | 12:00 AM | — |
| 5:00 AM | 1:00 AM | — |
| 6:00 AM | 2:00 AM | — |
| 7:00 AM | 3:00 AM | — |
| 8:00 AM | 4:00 AM | — |
| 9:00 AM | 5:00 AM | MT only |
| 10:00 AM | 6:00 AM | MT only |
| 11:00 AM | 7:00 AM | MT only |
| 12:00 PM | 8:00 AM | MT only |
| 1:00 PM | 9:00 AM | Both zones |
| 2:00 PM | 10:00 AM | Both zones |
| 3:00 PM | 11:00 AM | Both zones |
| 4:00 PM | 12:00 PM | Both zones |
| 5:00 PM | 1:00 PM | HST only |
| 6:00 PM | 2:00 PM | HST only |
| 7:00 PM | 3:00 PM | HST only |
| 8:00 PM | 4:00 PM | HST only |
| 9:00 PM | 5:00 PM | — |
| 10:00 PM | 6:00 PM | — |
| 11:00 PM | 7:00 PM | — |
What MT and HST Actually Are
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.
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.
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 MT
Cities on HST
Frequently Asked Questions
What is the time difference between MT and HST?
HST is 4 hours behind MT. That is the live figure. Taken strictly as written, the gap between MT and HST is 3 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM MT in HST?
9:00 AM MT is 5:00 AM HST.
What are the best hours to schedule a call between MT and HST?
Between 1:00 PM and 5:00 PM MT, which is 9:00 AM to 1:00 PM HST. Both sides are inside normal business hours through that window.
Does the difference between MT and HST 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.