HST — Hawaii Standard Time
See what HST means, where it is used, how it relates to HDT, and convert Hawaii Standard Time to other time zones.
Meaning and places used
HST stands for Hawaii Standard Time and is fixed at UTC-10. It is used in the United States, including Hawaii and other locations that observe this standard offset.
DST and HDT relationship
HST does not observe daylight saving time on this page's current rules, so the offset remains UTC-10 year-round. Where daylight time is referenced, HDT is the counterpart abbreviation used for Hawaii Daylight Time.
Convert HST to others
Compare HST with other time zones using the visual time grid and hour-by-hour table. Export schedules with ICS download or send times to Google Calendar and Gmail.
How to Convert HST to Other Time Zones
Open the HST converter page: Go to https://www.xconvert.com/time-converter/hst-time-zone to load a comparison grid with Hawaii Standard Time (HST) already in view. This layout is useful when you need to line up working hours in Honolulu with teams elsewhere in the United States, especially for remote meetings, travel planning, or customer support coverage.
Add comparison cities: Click + Add City and search for cities you want to compare against HST, such as Honolulu, Hilo, or East Honolulu for Hawaii-based scheduling, then add cities in other regions you work with. This is helpful for industries like tourism, logistics, and distributed tech teams that need to coordinate Hawaii schedules with mainland offices or international partners.
Select a time range on the grid: Click Select if needed, then drag across the colored timeline in the HST row to highlight a meeting window in purple; use the left and right handles to resize it, or drag the center to move it. For example, you can highlight a morning or afternoon block in HST and immediately compare how that range lands across the other city rows, which helps when setting business calls or planning airport transfers and hotel check-ins.
Export and share the result: After selecting a range, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is practical when you want to send a confirmed Hawaii meeting slot to clients, share a support handoff window with a distributed team, or save a travel itinerary event so each person sees the timing in their own local calendar.
About Hawaii Standard Time (HST)
HST stands for Hawaii Standard Time. Its exact offset is UTC-10, which means locations observing HST are ten hours behind Coordinated Universal Time.
Hawaii Standard Time is used in the United States. Principal cities associated with HST include East Honolulu, Hilo, Honolulu, Kailua, and Pearl City, making it the key reference time for scheduling across Hawaii-based business, government, tourism, and local services.
HST is a standard-time abbreviation, and its daylight saving counterpart is HDT. Other abbreviations that share the same UTC offset of UTC-10 include CKT, TAHT, and W, which can matter when reading international schedules, aviation timetables, or system logs that display offset-equivalent abbreviations instead of city names.
HST and Daylight Saving Time
HST is the standard-time form of Hawaii time, and its counterpart is HDT. When people compare seasonal abbreviations, this distinction matters because calendar invites, software dashboards, and travel systems may show either the standard-time label or the daylight-time label depending on the schedule being referenced.
The daylight saving counterpart for HST is HDT, but exact switch dates are not included here. If you are reviewing a contract deadline, meeting series, or travel booking that specifically mentions a seasonal change, it is important to confirm whether the schedule is labeled HST or HDT, because the abbreviation itself tells you which time standard is being used.
Frequently Asked Questions
What does HST stand for?
HST stands for Hawaii Standard Time. It is the standard time abbreviation used for Hawaii-related scheduling and is commonly seen in calendars, meeting invites, travel planning, and business communication involving Honolulu and other Hawaii cities.
Is HST the same as HDT?
No, HST and HDT are not the same abbreviation. HST is the standard-time abbreviation, while HDT is its daylight saving counterpart, so the label used in a schedule matters when you are interpreting a meeting time or published event.
Which cities use HST?
Principal cities associated with HST include East Honolulu, Hilo, Honolulu, Kailua, and Pearl City. These cities make HST especially relevant for Hawaii-based travel coordination, local business operations, and remote work planning with teams located in the United States.
What is the UTC offset for HST?
The UTC offset for HST is UTC-10. In practical terms, any calendar, server log, or timetable marked HST is aligned ten hours behind UTC, which helps when comparing Hawaii time with international schedules.
When does HST change?
HST has a daylight saving counterpart called HDT, so the abbreviation can change depending on whether a schedule is expressed in standard time or daylight time. When reviewing recurring meetings or archived records, always note whether the timestamp says HST or HDT, because that abbreviation is the clearest indicator of the time basis being used.
Which country uses HST?
HST is used in the United States. It is the main time reference for Hawaii-related cities such as Honolulu and Hilo, so it appears often in domestic travel bookings, customer service schedules, and regional business operations.
Are there other abbreviations with the same offset as HST?
Yes. Abbreviations that share the same UTC-10 offset include CKT, TAHT, and W. This is useful when comparing international systems or reading exported calendar data, because the same offset can appear under different abbreviations depending on the region or standard being referenced.