EST to AST Converter
Convert time between Eastern Standard Time (EST) and Atlantic Standard Time (AST)
Eastern Standard Time (EST)
Atlantic Standard Time (AST)
Time Difference
Atlantic Standard Time (AST) is 0 hours ahead of Eastern Standard Time (EST)
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Select Time
Quick Reference
| EST | AST |
|---|---|
| 21:00 | 22:00 |
| 23:00 | 00:00 |
| 01:00 | 02:00 |
| 03:00 | 04:00 |
| 05:00 | 06:00 |
| 07:00 | 08:00 |
| 09:00 | 10:00 |
| 11:00 | 12:00 |
| 13:00 | 14:00 |
| 15:00 | 16:00 |
| 17:00 | 18:00 |
| 19:00 | 20:00 |
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 EST to AST Time Conversion
Eastern Standard Time (EST) is UTC-5 and is used across the Eastern United States and Canada. Atlantic Standard Time (AST) is UTC-4 and is used in Atlantic Canada (Nova Scotia, New Brunswick, Prince Edward Island, and parts of Newfoundland and Labrador) as well as some Caribbean islands. AST is 1 hour ahead of EST.
This conversion is essential for business coordination between Eastern North America and Atlantic Canada, as well as for travel planning and communication across these regions. Understanding the time difference helps ensure accurate scheduling for business meetings, family calls, and coordinated activities across the Atlantic region.
Common Use Cases for EST to AST Conversion
Business & Work
- Scheduling meetings between Eastern US offices and Atlantic Canada operations
- Coordinating with Atlantic Canada business partners and clients
- Planning conference calls across the Eastern and Atlantic time zones
- Managing cross-border business operations
Personal & Travel
- Coordinating with family and friends in Atlantic Canada
- Planning travel to Nova Scotia, New Brunswick, or Prince Edward Island
- Scheduling events that include participants from both regions
- Understanding time differences for communications
Time Zone Information
Eastern Standard Time (EST)
- UTC Offset: UTC-5 (UTC-4 during EDT)
- IANA Timezone: America/New_York
- Daylight Saving: Second Sunday in March to First Sunday in November
- Major Cities: New York, Philadelphia, Atlanta, Miami, Boston
- Coverage: Eastern United States and Canada
Atlantic Standard Time (AST)
- UTC Offset: UTC-4 (UTC-3 during ADT)
- IANA Timezone: America/Halifax
- Daylight Saving: Second Sunday in March to First Sunday in November
- Major Cities: Halifax, Saint John, Charlottetown, St. John's
- Coverage: Atlantic Canada and some Caribbean islands
Quick Reference: EST to AST
Remember: AST is always 1 hour ahead of EST
Frequently Asked Questions
What is the time difference between EST and AST?
Eastern Standard Time (EST) is UTC-5, while Atlantic Standard Time (AST) is UTC-4. This means AST is 1 hour ahead of EST. When you have 10:00 AM in New York (EST), it's 11:00 AM in Halifax (AST).
Why is AST only 1 hour ahead despite the distance?
AST is Atlantic Standard Time used in Canada's Atlantic provinces. While the geographic distance between New York and Halifax is significant, the time zone difference is only 1 hour because AST is UTC-4, positioned between the Eastern (UTC-5) and some European zones. Atlantic Canada is positioned to the east, hence one hour ahead.
Does AST observe daylight saving time like EST?
No, Atlantic Standard Time (AST) does not observe daylight saving time. It remains UTC-4 throughout the year. However, some Atlantic provinces observe Atlantic Daylight Time (ADT, UTC-3) during summer months. EST observes Eastern Daylight Time (EDT, UTC-4) from March to November, so the difference changes from 1 hour to effectively 2 hours.
What are the best times to schedule calls between Eastern US and Atlantic Canada?
Business hour overlap is good due to the 1-hour difference. Morning meetings (9-11 AM EST) correspond to 10 AM-12 PM AST. Afternoon meetings (2-4 PM EST) correspond to 3-5 PM AST. The entire business day has good overlap for both regions, making coordination easier.
Why is EST to AST conversion important for business?
Eastern US cities (Boston, New York, Philadelphia) have significant connections to Atlantic Canada (Halifax, Saint John). Many Canadian companies headquartered or operating in Atlantic Canada work with Eastern US businesses. This includes tourism, maritime, energy, and trade operations requiring regular coordination.
Do all Atlantic Canadian provinces observe the same time?
Most Atlantic provinces use AST (UTC-4) year-round, but Newfoundland and Labrador observe Newfoundland Standard Time (NST, UTC-3:30), which is 30 minutes different. This unique 30-minute offset can affect scheduling for St. John's and other Newfoundland locations, making them 1.5 hours ahead of EST.
Pro Tips
- • EST to AST is 1 hour - a simple conversion between Eastern US and most of Atlantic Canada (year-round). Verify which provinces/times apply.
- • AST does not observe daylight saving time, remaining constant year-round. This makes it a static reference unlike EST which changes seasonally.
- • Schedule morning calls (9-10 AM EST) for 10-11 AM AST to catch both regions at the start of the workday.
- • Atlantic Canada has unique business advantages: strategic location for North Atlantic trade, strong fisheries, and oil/gas industry.
- • Use the 3 PM EST window (4 PM AST) for important meetings between Eastern and Atlantic regions.
- • Always verify if you're scheduling with Newfoundland, as it observes NST (UTC-3:30), which is 1.5 hours ahead of EST.
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