AST to HST Converter
Understanding AST and HST Time Zones
Atlantic Standard Time (AST)
Atlantic Standard Time is observed in undefined and uses the offset UTC-4. Major cities in this time zone include Halifax, San Juan. This time zone serves a significant global region with important economic and cultural hubs.
Hawaii Standard Time (HST)
Hawaii Standard Time operates at UTC-10, covering undefined. Key cities include Honolulu, Maui. The 6-hour backward offset from AST means that when professionals in Halifax start their workday at 9:00 AM, it is already 3:00 AM in Honolulu.
AST is also commonly referred to as Atlantic Time, Puerto Rico time. HST is also known as Hawaii Time, Honolulu time, Hawaiian time. So if you are searching for Atlantic Time to Hawaii Time, this is the same conversion as AST to HST.
Complete AST to HST Conversion Table
The table below shows every two-hour increment converted from Atlantic Standard Time to Hawaii Standard Time. Business hours (9 AM – 5 PM) are highlighted for easy scheduling reference.
| AST (Atlantic Standard Time) | HST (Hawaii Standard Time) |
|---|---|
| 12:00 AM (00:00) | 6:00 PM (18:00) (previous day) |
| 2:00 AM (02:00) | 8:00 PM (20:00) (previous day) |
| 4:00 AM (04:00) | 10:00 PM (22:00) (previous day) |
| 6:00 AM (06:00) | 12:00 AM (00:00) |
| 8:00 AM (08:00) | 2:00 AM (02:00) |
| 10:00 AM (10:00) | 4:00 AM (04:00) |
| 12:00 PM (12:00) | 6:00 AM (06:00) |
| 2:00 PM (14:00) | 8:00 AM (08:00) |
| 4:00 PM (16:00) | 10:00 AM (10:00) |
| 6:00 PM (18:00) | 12:00 PM (12:00) |
| 8:00 PM (20:00) | 2:00 PM (14:00) |
| 10:00 PM (22:00) | 4:00 PM (16:00) |
Times shown in 12-hour and 24-hour format. Last updated 2026-03-09.
Scheduling Between AST and HST
International conference calls between Halifax, San Juan and Honolulu, Maui work best when scheduled during the overlap of both regions' business hours. Rotating meeting times monthly ensures fairness across time zones.
The moderate 6-hour gap between AST and HST 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 Halifax and Honolulu
Booking hotels and transportation in Honolulu? Double-check whether listed check-in times are in HST (local) or your departure time zone. A common mistake is arriving 6 hours early or late due to unconverted times.
Medical experts recommend allowing approximately one day of adjustment per hour of time difference. For the 6-hour shift between AST and HST, plan for about 6 days to fully acclimate.
Daylight Saving Time Considerations
When daylight saving time is in effect, the abbreviation changes (e.g., EST becomes EDT, CET becomes CEST). Our converter handles this automatically, but being aware of which version is active helps avoid confusion.
For the AST to HST conversion specifically: AST (UTC-4) and HST (UTC-10) neither observes DST, so the 6-hour offset remains constant throughout the year. This makes scheduling reliable and predictable.
Related Time Zone Conversions
References & Resources
Frequently Asked Questions
AST (Atlantic Standard Time) is 6 hours ahead of HST (Hawaii Standard Time). AST is UTC-4 and HST is UTC-10.
When it is 12:00 PM (noon) in AST, it is 6:00 AM in HST.
The best overlap for business hours is approximately 3:00 AM to 11:00 AM HST, which corresponds to 9:00 AM to 5:00 PM in AST.
When daylight saving time is in effect, the abbreviation changes (e.g., EST becomes EDT, CET becomes CEST). Our converter handles this automatically, but being aware of which version is active helps avoid confusion.