HST to PDT Converter
Convert time between Hawaii Standard Time (HST) and Pacific Daylight Time (PDT)
Hawaii Standard Time (HST)
Pacific Daylight Time (PDT)
Time Difference
Pacific Daylight Time (PDT) is 0 hours ahead of Hawaii Standard Time (HST)
Select Date
Select Time
Quick Reference
| HST | PDT |
|---|---|
| 16:00 | 18:00 |
| 18:00 | 20:00 |
| 20:00 | 22:00 |
| 22:00 | 00:00 |
| 00:00 | 02:00 |
| 02:00 | 04:00 |
| 04:00 | 06:00 |
| 06:00 | 08:00 |
| 08:00 | 10:00 |
| 10:00 | 12:00 |
| 12:00 | 14:00 |
| 14:00 | 16:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
Related Time Zone Conversions
About HST to PDT Time Conversion
Converting time between Hawaii Standard Time (HST) and Pacific Daylight Time (PDT) is important for coordinating between Hawaii and the US West Coast during daylight saving time. HST is UTC-10, while PDT is UTC-7, making PDT 3 hours ahead of HST. Hawaii does not observe daylight saving time, but the West Coast does, adding complexity to the conversion.
This conversion is vital for business operations between Hawaii and the mainland US West Coast, including California, Washington, and Oregon. Understanding this time difference is crucial for scheduling meetings, managing customer service, and coordinating operations between these important economic regions, especially during the March-November daylight saving period.
Common Use Cases for HST to PDT Conversion
Business & Work
- Scheduling calls between Hawaii offices and West Coast headquarters during daylight saving time
- Coordinating shipping and logistics operations across Pacific regions
- Managing tourism reservations and customer service across Hawaii-West Coast
Personal & Travel
- Scheduling video calls with family and friends in California, Oregon, or Washington
- Planning travel between Hawaii and the West Coast
- Coordinating vacation and leisure time across regions during spring and summer months
Time Zone Information
Hawaii Standard Time (HST)
- UTC Offset: UTC-10
- IANA Timezone: Pacific/Honolulu
- Daylight Saving: No daylight saving time observed
- Major Cities: Honolulu, Hilo, Maui, Kauai, Big Island
- Coverage: State of Hawaii
Pacific Daylight Time (PDT)
- UTC Offset: UTC-7 (UTC-8 during PST)
- IANA Timezone: America/Los_Angeles
- Daylight Saving: Second Sunday in March to First Sunday in November
- Major Cities: Los Angeles, San Francisco, Seattle, San Diego, Portland, Sacramento
- Coverage: Pacific Coast United States and Canada
Quick Reference: HST to PDT
Remember: PDT is always 3 hours ahead of HST during daylight saving time (March-November). Outside this period, PST is 2 hours ahead of HST
Frequently Asked Questions
What is the time difference between HST and PDT?
Hawaii Standard Time (HST) is UTC-10, while Pacific Daylight Time (PDT) is UTC-7. PDT is 3 hours ahead of HST. This means when it's 8:00 AM in HST, it's 11:00 AM the same day in PDT.
Does Hawaii observe daylight saving time?
No, Hawaii does not observe daylight saving time. Hawaii Standard Time (HST) remains UTC-10 year-round. However, the West Coast observes daylight saving time, transitioning from PST (UTC-8) to PDT (UTC-7). This means the time difference varies between 2 hours (when PST is active, November-March) and 3 hours (when PDT is active, March-November).
How does HST to PDT differ from HST to PST?
PDT (Pacific Daylight Time) is 1 hour ahead of PST (Pacific Standard Time). When PDT is active (March-November), the difference between HST and PDT is 3 hours. When PST is active (November-March), the difference between HST and PST is 2 hours. PDT is used during daylight saving time on the West Coast.
What major cities are in HST and PDT timezones?
HST covers Hawaii cities including Honolulu, Hilo, Maui, Kauai, and the Big Island. PDT covers major West Coast cities like Los Angeles, San Francisco, Seattle, San Diego, Portland, and Sacramento during daylight saving time (March-November). These regions represent Hawaii and the Pacific Coast of the continental US during summer months.
How do I convert HST to PDT manually?
To convert from HST to PDT, add 3 hours to the HST time. For example, if it's 9:00 AM HST, it would be 12:00 PM (noon) PDT the same day. Remember this conversion is only valid during daylight saving time (March-November). When PST is active (November-March), add only 2 hours instead.
What should I know about scheduling across HST and PDT?
Hawaii is 3 hours behind the West Coast during PDT, making coordination easier than with the East Coast. Morning PDT times (8-10 AM) correspond to early morning HST times (5-7 AM), and late afternoon PDT (3-5 PM) corresponds to late morning HST (12-2 PM). For regular business coordination, early morning PDT calls (7-9 AM) work well with Hawaii (4-6 AM HST for early birds, or 4-6 PM HST for evening workers).
Pro Tips
- • PDT is always 3 hours ahead of HST during daylight saving time (March-November). Outside this period, PST is 2 hours ahead.
- • Hawaii does not observe daylight saving time, so HST is consistent year-round while PDT changes twice annually.
- • Late afternoon PDT (3-5 PM) aligns well with late morning/early afternoon HST (12-2 PM) for mid-day meetings.
- • Morning hours (7-9 AM PDT = 4-6 AM HST) work for early risers in Hawaii coordinating with West Coast business hours.
- • Use 24-hour time format when communicating across HST-PDT to eliminate AM/PM confusion, especially around morning/evening transitions.
- • Technology, entertainment, and tourism businesses between Hawaii and the West Coast can easily coordinate during shared business hours and peak seasons.