CET to AST Converter
Convert time between Central European Time (CET) and Atlantic Standard Time (AST)
Central European Time (CET)
Atlantic Standard Time (AST)
Time Difference
Atlantic Standard Time (AST) is 0 hours ahead of Central European Time (CET)
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Select Time
Quick Reference
| CET | AST |
|---|---|
| 03:00 | 22:00 |
| 05:00 | 00:00 |
| 07:00 | 02:00 |
| 09:00 | 04:00 |
| 11:00 | 06:00 |
| 13:00 | 08:00 |
| 15:00 | 10:00 |
| 17:00 | 12:00 |
| 19:00 | 14:00 |
| 21:00 | 16:00 |
| 23:00 | 18:00 |
| 01:00 | 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 CET to AST Time Conversion
Converting time between Central European Time (CET) and Atlantic Standard Time (AST) is essential for coordination between Europe and Atlantic Canada. CET is UTC+1, while AST is UTC-4, making AST 5 hours behind CET.
This conversion is crucial for international business operations spanning Europe and Atlantic Canada, including major cities like Halifax, Saint John, and St. John's. Both regions observe daylight saving time, with CET transitioning to CEST (UTC+2) from March to October, and ADT (Atlantic Daylight Time, UTC-3) being active from March to November. This means the actual difference can vary between 4 and 5 hours depending on the time of year.
Common Use Cases for CET to AST Conversion
Business & Work
- Scheduling transatlantic business meetings between Europe and Atlantic Canada
- Coordinating operations between European and Atlantic Canadian regional offices
- Managing international teams across Europe and Maritime provinces
- Planning conference calls with distributed global teams in Atlantic time zone
- Coordinating with maritime industries, tech companies, and energy sectors in Atlantic Canada
Personal & Travel
- Coordinating with family and friends in Europe from Atlantic Canada
- Planning travel between Europe and Atlantic Canadian cities
- Scheduling virtual events and online meetings across time zones
- Coordinating online classes, training, or collaboration sessions
- Tracking European events and live broadcasts from Atlantic Canada
Time Zone Information
Central European Time (CET)
- UTC Offset: UTC+1 (UTC+2 during CEST)
- IANA Timezone: Europe/Paris
- Daylight Saving: Last Sunday in March to Last Sunday in October
- Major Cities: Paris, Berlin, Amsterdam, Brussels, Vienna, Prague, Milan, Madrid
- Coverage: Central Europe including France, Germany, Spain, Italy, Poland, and more
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 (ADT)
- Major Cities: Halifax, Saint John, St. John's, Moncton, Cape Breton
- Coverage: Atlantic Canada including Nova Scotia, New Brunswick, Newfoundland and Labrador
Quick Reference: CET to AST
Note: AST is always 5 hours behind CET (November-March when AST is active), or 4 hours behind when ADT (UTC-3) is active (March-November)
Frequently Asked Questions
What is the time difference between CET and AST?
Central European Time (CET) is UTC+1, while Atlantic Standard Time (AST) is UTC-4. This means CET is 5 hours ahead of AST. When you have 12:00 PM in Paris (CET), it's 7:00 AM in Halifax (AST) the same day. During summer months when ADT (UTC-3) is active instead of AST, the difference becomes 4 hours.
How does the CET to AST offset compare to other North American time zones?
AST is 1 hour ahead of EDT (Eastern) and 1 hour behind CDT (Central). Since CET is 5 hours ahead of AST, it's 4 hours ahead of EDT and 6 hours ahead of CDT. Atlantic Canada offers excellent middle ground for Europe-North America coordination.
Does Europe observe daylight saving time like AST does?
Yes, Europe observes daylight saving time. CET transitions to CEST (Central European Summer Time, UTC+2) from the last Sunday in March to the last Sunday in October. AST transitions to ADT (Atlantic Daylight Time, UTC-3) from the second Sunday in March to the first Sunday in November. These transitions happen on different dates, creating periods where the offset is either 4 or 5 hours.
When do the daylight saving time transitions occur?
Europe transitions to summer time on the last Sunday in March and back to standard time on the last Sunday in October. Atlantic Canada transitions to daylight time on the second Sunday in March and back to standard time on the first Sunday in November. This means there are 1-2 week periods where the offset differs by one hour when only one region is in daylight saving time.
What are the best times to schedule calls between Europe and Atlantic Canada?
Due to the 5-hour difference, overlapping business hours are limited. Early morning in Europe (7-9 AM CET) overlaps with very early morning in Atlantic Canada (2-4 AM AST). Late afternoon in Europe (4-6 PM CET) overlaps with late morning in Atlantic Canada (11 AM-1 PM AST). The 4-6 PM CET window (11 AM-1 PM AST) offers the best afternoon-morning overlap for both regions.
Why is Atlantic Canada important for Europe-North America business?
Atlantic Canada serves as a gateway between Europe and North America. Halifax is a major port city with significant maritime industries, tech hubs, and financial services. The geographic location on the Atlantic coast makes it a natural hub for international business. The 5-hour offset with Europe is the smallest among North American time zones, providing excellent business hour overlap.
Pro Tips
- • Europe transitions on the last Sunday of March and October, while Atlantic Canada transitions on the second Sunday of March and first Sunday of November. Mark your calendar for these dates as they create temporary offset changes.
- • The 5-hour gap is the smallest among North American time zones - a 5 PM CET call is 12 noon AST. The 4-6 PM CET window (11 AM-1 PM AST) works well for both regions.
- • European morning standups (9 AM CET) overlap with Atlantic Canada midnight (4 AM AST). Consider scheduling critical discussions at 4-5 PM CET (11 AM-12 PM AST) instead, when both teams are alert.
- • Halifax office hours (9 AM-5 PM AST) align with 2-10 PM CET the same day - excellent evening overlap for European work.
- • Always confirm meeting times in both CET and AST in writing. Time zone confusion is common - document in both zones to prevent scheduling errors.
- • The 4-6 PM CET window (11 AM-1 PM AST) is prime time for Europe-Atlantic Canada meetings. Use this "golden hour" for synchronous collaboration and important discussions.
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