HST to MST Converter
MST is 3 hours ahead of HST. 9:00 AM HST = 12:00 PM MST.
MST is 3 hours ahead of HST at the moment. To convert HST to MST, add 3 hours to the HST time: 9:00 AM HST = 12:00 PM MST.
HST (Hawaii-Aleutian Time) is used in Hawaii (all year, no daylight saving time). MST (Mountain Time) is used in Denver, Salt Lake City, Albuquerque, Calgary, Edmonton; Phoenix (Arizona) all year.
Most of Arizona uses MST all year and does not switch to MDT.
HST to MST time conversion table
HST to MST on 6 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| HST | MST | Day |
|---|---|---|
| 12:00 AM HST | 3:00 AM MST | night |
| 1:00 AM HST | 4:00 AM MST | night |
| 2:00 AM HST | 5:00 AM MST | night |
| 3:00 AM HST | 6:00 AM MST | — |
| 4:00 AM HST | 7:00 AM MST | — |
| 5:00 AM HST | 8:00 AM MST | — |
| 6:00 AM HST | 9:00 AM MST | — |
| 7:00 AM HST | 10:00 AM MST | — |
| 8:00 AM HST | 11:00 AM MST | — |
| 9:00 AM HST | 12:00 PM MST | work hours |
| 10:00 AM HST | 1:00 PM MST | work hours |
| 11:00 AM HST | 2:00 PM MST | work hours |
| 12:00 PM HST | 3:00 PM MST | work hours |
| 1:00 PM HST | 4:00 PM MST | work hours |
| 2:00 PM HST | 5:00 PM MST | — |
| 3:00 PM HST | 6:00 PM MST | — |
| 4:00 PM HST | 7:00 PM MST | — |
| 5:00 PM HST | 8:00 PM MST | — |
| 6:00 PM HST | 9:00 PM MST | — |
| 7:00 PM HST | 10:00 PM MST | night |
| 8:00 PM HST | 11:00 PM MST | night |
| 9:00 PM HST | 12:00 AM MST | next day |
| 10:00 PM HST | 1:00 AM MST | next day |
| 11:00 PM HST | 2:00 AM MST | next day |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert HST to MST
Add 3 hours to the HST time to get MST.
Example: 9:00 AM HST = 12:00 PM MST.
Across midnight: 10:00 PM HST = 1:00 AM MST (next day). The date changes, so always check the day as well as the hour.
Time difference between HST and MST
The time difference between HST and MST is not the same all year, because the two sides change for daylight saving time on different dates. In 2026 it works out like this:
- 31 Dec 2025 – 6 Mar 2026: MST is 3 hours ahead of HST.
- 7 Mar 2026 – 30 Oct 2026: MST is 4 hours ahead of HST.
- 31 Oct 2026 – 30 Dec 2026: MST is 3 hours ahead of HST.
HST and MST during daylight saving time
- HST does not observe daylight saving time; it stays on UTC−10 all year.
- MST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from MST (UTC−7) to MDT (UTC−6).
Best time for a meeting between HST and MST
HST and MST share 5 hours of the 9 AM–5 PM working day. Any time between 9:00 AM and 2:00 PM HST lands between 12:00 PM and 5:00 PM MST, inside working hours for both.
HST to MST FAQ
What is the time difference between HST and MST?
Right now MST is 3 hours ahead of HST. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM HST in MST?
9:00 AM HST is 12:00 PM MST.
What is 12 PM (noon) HST in MST?
12:00 PM HST is 3:00 PM MST.
Is MST ahead of or behind HST?
MST is 3 hours ahead of HST, so it is later in MST than in HST.
Does HST change for daylight saving time?
No. HST stays on the same offset all year, so conversions never shift for daylight saving time.
Does MST change for daylight saving time?
Yes. MST next changes on 14 Mar 2027, when clocks go forward one hour from MST to MDT.
What is the best time for a meeting between HST and MST?
HST and MST share 5 hours of the 9 AM–5 PM working day. Any time between 9:00 AM and 2:00 PM HST lands between 12:00 PM and 5:00 PM MST, inside working hours for both.
Is MT the same as MST?
MST is the winter (standard) name of Mountain Time (MT). From March to November the same clocks are called MDT. This converter always uses the one in force on the date you choose.
Related conversions
Convert MST to HST
Convert HST to other time zones
Convert other time zones to MST
Learn more
Updated 6 November 2026. Time zone data: IANA tz database.