HST to MDT Converter
Understanding HST and MDT Time Zones
Hawaii Standard Time (HST)
Hawaii Standard Time is observed in undefined and uses the offset UTC-10. Major cities in this time zone include Honolulu, Maui. This time zone serves a significant global region with important economic and cultural hubs.
Mountain Daylight Time (MDT)
Mountain Daylight Time operates at UTC-6, covering undefined. Key cities include Denver, Salt Lake City, Albuquerque. The 4-hour forward offset from HST means that when professionals in Honolulu start their workday at 9:00 AM, it is already 1:00 PM in Denver.
HST is also commonly referred to as Hawaii Time, Honolulu time, Hawaiian time. MDT is also known as Mountain Time, Mountain Daylight, MT, Denver time. So if you are searching for Hawaii Time to Mountain Time, this is the same conversion as HST to MDT.
Complete HST to MDT Conversion Table
The table below shows every two-hour increment converted from Hawaii Standard Time to Mountain Daylight Time. Business hours (9 AM – 5 PM) are highlighted for easy scheduling reference.
| HST (Hawaii Standard Time) | MDT (Mountain Daylight Time) |
|---|---|
| 12:00 AM (00:00) | 4:00 AM (04:00) |
| 2:00 AM (02:00) | 6:00 AM (06:00) |
| 4:00 AM (04:00) | 8:00 AM (08:00) |
| 6:00 AM (06:00) | 10:00 AM (10:00) |
| 8:00 AM (08:00) | 12:00 PM (12:00) |
| 10:00 AM (10:00) | 2:00 PM (14:00) |
| 12:00 PM (12:00) | 4:00 PM (16:00) |
| 2:00 PM (14:00) | 6:00 PM (18:00) |
| 4:00 PM (16:00) | 8:00 PM (20:00) |
| 6:00 PM (18:00) | 10:00 PM (22:00) |
| 8:00 PM (20:00) | 12:00 AM (00:00) (next day) |
| 10:00 PM (22:00) | 2:00 AM (02:00) (next day) |
Times shown in 12-hour and 24-hour format. Last updated 2026-03-09.
Scheduling Between HST and MDT
For business scheduling, the optimal overlap window between HST and MDT falls roughly between 9:00 AM and 1:00 PM HST. This ensures both Honolulu and Denver teams are within standard working hours.
The moderate 4-hour gap between HST and MDT means that there is a partial overlap of business hours. Teams can typically find a 3–4 hour window that works for both sides without requiring anyone to work outside normal hours.
Travel Between Honolulu and Denver
Travelers flying from Honolulu to Denver should adjust their sleep schedule 4 days before departure at a rate of one hour per day. For this time difference, gradual adjustment reduces jet lag dramatically.
Medical experts recommend allowing approximately one day of adjustment per hour of time difference. For the 4-hour shift between HST and MDT, plan for about 4 days to fully acclimate.
Daylight Saving Time Considerations
During standard time months (November through March in the US), this offset is fixed. However, if either zone observes daylight saving time, the difference may temporarily shift by one hour during transition weeks in spring and autumn.
For the HST to MDT conversion specifically: HST (UTC-10) does not observe DST, while MDT (UTC-6) does observe DST. This means the offset between them changes by one hour seasonally — the usual 4-hour gap becomes 3 or 5 hours during DST transitions.
Related Time Zone Conversions
References & Resources
Frequently Asked Questions
HST (Hawaii Standard Time) is 4 hours behind MDT (Mountain Daylight Time). HST is UTC-10 and MDT is UTC-6.
When it is 12:00 PM (noon) in HST, it is 4:00 PM in MDT.
The best overlap for business hours is approximately 1:00 PM to 9:00 PM MDT, which corresponds to 9:00 AM to 5:00 PM in HST.
During standard time months (November through March in the US), this offset is fixed. However, if either zone observes daylight saving time, the difference may temporarily shift by one hour during transition weeks in spring and autumn.