HST to ART Time Converter
ART is 7 hours ahead of HST. HST is UTC-10:00, and ART is UTC-3:00.
Best Time to Call Between HST and ART
Both zones are inside normal business hours between 9:00 AM and 10:00 AM HST — that's 4:00 PM to 5:00 PM ART. That's a 1-hour window.
both at work HST only ART only neither — hours along the strip are HST.
Common Times Converted
HST on the left, ART on the right.
HST to ART: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| HST | ART | Working hours |
|---|---|---|
| 12:00 AM | 7:00 AM | — |
| 1:00 AM | 8:00 AM | — |
| 2:00 AM | 9:00 AM | ART only |
| 3:00 AM | 10:00 AM | ART only |
| 4:00 AM | 11:00 AM | ART only |
| 5:00 AM | 12:00 PM | ART only |
| 6:00 AM | 1:00 PM | ART only |
| 7:00 AM | 2:00 PM | ART only |
| 8:00 AM | 3:00 PM | ART only |
| 9:00 AM | 4:00 PM | Both zones |
| 10:00 AM | 5:00 PM | HST only |
| 11:00 AM | 6:00 PM | HST only |
| 12:00 PM | 7:00 PM | HST only |
| 1:00 PM | 8:00 PM | HST only |
| 2:00 PM | 9:00 PM | HST only |
| 3:00 PM | 10:00 PM | HST only |
| 4:00 PM | 11:00 PM | HST only |
| 5:00 PM | 12:00 AM next day | — |
| 6:00 PM | 1:00 AM next day | — |
| 7:00 PM | 2:00 AM next day | — |
| 8:00 PM | 3:00 AM next day | — |
| 9:00 PM | 4:00 AM next day | — |
| 10:00 PM | 5:00 AM next day | — |
| 11:00 PM | 6:00 AM next day | — |
What HST and ART Actually Are
HST — Hawaii Standard Time
Honolulu and the rest of Hawaii. Standing at UTC-10:00 as written, and the region does not change its clocks, so that offset holds all year. Hawaii does not observe daylight saving, so this offset holds all year.
Hawaii dropped daylight saving in 1967 and never resumed it. Being close to the equator, its daylight barely varies across the year, so there is little to gain.
ART — Argentina Time
Buenos Aires, Córdoba, Rosario. Standing at UTC-3:00 as written, and the region does not change its clocks, so that offset holds all year. Argentina does not observe daylight saving, so this offset is fixed year-round.
Argentina has changed its time zone rules more than a dozen times since 1930 and abandoned daylight saving in 2009.
What This Means in Practice
A gap you can rely on
Neither region changes its clocks, so this difference holds every day of the year. A recurring meeting booked once stays correct — worth knowing, because most cross-border pairs cannot say that.
Major Cities in Each Zone
Cities on HST
Cities on ART
Frequently Asked Questions
What is the time difference between HST and ART?
ART is 7 hours ahead of HST.
What is 9:00 AM HST in ART?
9:00 AM HST is 4:00 PM ART.
What are the best hours to schedule a call between HST and ART?
Between 9:00 AM and 10:00 AM HST, which is 4:00 PM to 5:00 PM ART. Both sides are inside normal business hours through that window.
Does the difference between HST and ART change during the year?
No. Neither region changes its clocks, so this gap is fixed all year round.
Does HST always mean Hawaii Standard Time?
Hawaii does not observe daylight saving, so this offset holds all year.
Does ART always mean Argentina Time?
Argentina does not observe daylight saving, so this offset is fixed year-round.