What is HST in MST?
Mountain Time is 4 hours ahead
Hawaii Standard Time is on UTC−10:00 and Mountain Time is on UTC−6:00 right now. Mountain Time is on daylight saving, so its clocks read MDT. The gap changes during the year — see below.
- Time in Honolulu
- 4:14 pm
- Time in Denver
- 8:14 pm
- Difference
- +4 h
- Next clock change
- November 1, 2026
Convert a time
MDT — Mountain Time
8:00 pm
Tue
When the difference changes
Hawaii Standard Time and Mountain Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:
- Now – November 1, 2026Mountain Time is 4 hours ahead
- November 1, 2026 – March 14, 2027Mountain Time is 3 hours ahead
- March 14, 2027 – onwardsMountain Time is 4 hours ahead
Periods shorter than a day are not listed: both zones change at 2am in their own local time, so there are a few hours on each transition date when the gap is briefly something else.
Daylight saving
Hawaii Standard Time
Hawaii Standard Time stays on HST all year, so its offset from UTC never moves.
Mountain Time
Clocks go back one hour at 2am local time, becoming MST.
HST to MST conversion table
Every hour of Tuesday, September 22, 2026, converted from Hawaii Standard Time to Mountain Time. 4 of the 24 hours fall on a different calendar day in Denver, which is marked.
- 12:00 am HST
- 4:00 am MDT
- 1:00 am HST
- 5:00 am MDT
- 2:00 am HST
- 6:00 am MDT
- 3:00 am HST
- 7:00 am MDT
- 4:00 am HST
- 8:00 am MDT
- 5:00 am HST
- 9:00 am MDT
- 6:00 am HST
- 10:00 am MDT
- 7:00 am HST
- 11:00 am MDT
- 8:00 am HST
- 12:00 pm MDT
- 9:00 am HST
- 1:00 pm MDT
- 10:00 am HST
- 2:00 pm MDT
- 11:00 am HST
- 3:00 pm MDT
- 12:00 pm HST
- 4:00 pm MDT
- 1:00 pm HST
- 5:00 pm MDT
- 2:00 pm HST
- 6:00 pm MDT
- 3:00 pm HST
- 7:00 pm MDT
- 4:00 pm HST
- 8:00 pm MDT
- 5:00 pm HST
- 9:00 pm MDT
- 6:00 pm HST
- 10:00 pm MDT
- 7:00 pm HST
- 11:00 pm MDT
- 8:00 pm HST
- 12:00 am MDT+1 day
- 9:00 pm HST
- 1:00 am MDT+1 day
- 10:00 pm HST
- 2:00 am MDT+1 day
- 11:00 pm HST
- 3:00 am MDT+1 day
Scheduling between the two
Working hours overlap from 9:00 am to 2:00 pm HST, which is 1:00 pm to 6:00 pm MDT. Anything inside that window falls in the normal working day at both ends.
Hawaii Standard Time (HST) is used in all of Hawaii, which does not observe daylight saving
Mountain Time (MDT) is used in Salt Lake City, Albuquerque and Calgary. Arizona keeps MST all year and does not follow MDT.