Convert Hawaii Standard Time to Mountain Daylight Time
Instantly convert Hawaii Standard Time (HST) to Mountain Daylight Time (MDT) with our free online calculator.
Hawaii Standard Time
07:20:48 PM
Tue, Jun 23 (HST)
Mountain Daylight Time
11:20:48 PM
Tue, Jun 23 (MDT)
Convert a Specific Time
24-Hour Comparison
| HST | MDT |
|---|---|
| 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 |
| 6:00 AM | 10:00 AM |
| 7:00 AM | 11:00 AM |
| 8:00 AM | 12:00 PM |
| 9:00 AM | 1:00 PM |
| 10:00 AM | 2:00 PM |
| 11:00 AM | 3:00 PM |
| 12:00 PM | 4:00 PM |
| 1:00 PM | 5:00 PM |
| 2:00 PM | 6:00 PM |
| 3:00 PM | 7:00 PM |
| 4:00 PM | 8:00 PM |
| 5:00 PM | 9:00 PM |
| 6:00 PM | 10:00 PM |
| 7:00 PM | 11:00 PM |
| 8:00 PM | 12:00 AM(+1d) |
| 9:00 PM | 1:00 AM(+1d) |
| 10:00 PM | 2:00 AM(+1d) |
| 11:00 PM | 3:00 AM(+1d) |
How to Convert Hawaii Standard Time to Mountain Daylight Time
Formula
To convert Hawaii Standard Time (HST) to Mountain Daylight Time (MDT): Convert HST to MDT
About Hawaii Standard Time (HST)
Hawaii Standard Time (HST, IANA: Pacific/Honolulu) is the time zone for the State of Hawaii and the Aleutian Islands of Alaska west of 169.5°W. HST is UTC-10:00 year-round and does not observe Daylight Saving Time per Hawaii Revised Statutes §1-31 (Hawaii opted out of the Uniform Time Act of 1966). When the US mainland switches to Daylight Saving Time in March, the offset from Hawaii to the West Coast (Pacific Time) becomes 3 hours instead of the standard 2 hours. Honolulu sees solar noon at approximately 12:30 PM HST in summer. HST is the same offset as Cook Island Time (CKT) and Tahiti Time (TAHT) in French Polynesia, allowing easy mental conversion across the central Pacific. Time-sensitive activities affected by HST include Pacific tsunami warning system coordination per NOAA NTWC, US military operations from Joint Base Pearl Harbor-Hickam, and the Mauna Kea astronomical observatories' nightly observing schedules.
About Mountain Daylight Time (MDT)
Mountain Daylight Time (MDT, IANA: America/Denver during DST window) is the summer-time variant of MST, set at UTC-6:00 — observed from the second Sunday in March to the first Sunday in November per the Energy Policy Act of 2005. MDT shares the same UTC offset as Central Standard Time (CST), which can cause cross-time-zone scheduling confusion during the DST transition windows in March and November. The Navajo Nation in northeastern Arizona does observe MDT (unlike the rest of Arizona), creating one of the rare US sub-state time-zone exceptions per the Navajo Nation Council's 1968 resolution. MDT applies in Colorado, Utah, Wyoming, Montana, Idaho east, New Mexico, parts of Texas, and Canadian Rocky Mountain provinces (Alberta, eastern BC). Used in coordination of: Denver International Airport flight operations, ski-area lift hours during shoulder-season DST window, Yellowstone National Park ranger schedules, US National Renewable Energy Lab operations, and FAA Albuquerque ARTCC ATC operations.