PST to AST Converter
Convert time between Pacific Standard Time (PST) and Atlantic Standard Time (AST)
Pacific Standard Time (PST)
Atlantic Standard Time (AST)
Time Difference
Atlantic Standard Time (AST) is 0 hours ahead of Pacific Standard Time (PST)
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Select Time
Quick Reference
| PST | AST |
|---|---|
| 18:00 | 22:00 |
| 20:00 | 00:00 |
| 22:00 | 02:00 |
| 00:00 | 04:00 |
| 02:00 | 06:00 |
| 04:00 | 08:00 |
| 06:00 | 10:00 |
| 08:00 | 12:00 |
| 10:00 | 14:00 |
| 12:00 | 16:00 |
| 14:00 | 18:00 |
| 16:00 | 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 PST to AST Time Conversion
Converting time between Pacific Standard Time (PST) and Atlantic Standard Time (AST) is essential for coordinating across North America's coasts. PST is UTC-8 and is used across the Pacific United States and Canada (November to March), while AST is UTC-4 and is used in Atlantic Canada (Nova Scotia, New Brunswick, Prince Edward Island, and parts of Newfoundland and Labrador). AST is 4 hours ahead of PST.
This conversion is crucial for business coordination between West Coast and Atlantic Canada, travel planning, and communication across these distant regions. Understanding the 4-hour time difference helps ensure accurate scheduling for business meetings, family calls, and coordinated activities spanning both coasts of North America.
Common Use Cases for PST to AST Conversion
Business & Work
- Scheduling meetings between Pacific West Coast and Atlantic Canada offices
- Coordinating with Atlantic Canada business partners and clients
- Planning conference calls across the Pacific and Atlantic time zones
- Managing distributed teams across North American coasts
Personal & Travel
- Coordinating with family and friends in Atlantic Canada
- Planning travel from Pacific Coast to Maritime provinces
- Scheduling events that include participants from both regions
- Understanding time differences for remote communications
Time Zone Information
Pacific Standard Time (PST)
- UTC Offset: UTC-8 (UTC-7 during PDT)
- 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, Vancouver
- Coverage: Pacific 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: PST to AST
Remember: AST is always 4 hours ahead of PST
Frequently Asked Questions
What is the time difference between PST and AST?
Pacific Standard Time (PST) is UTC-8, while Atlantic Standard Time (AST) is UTC-4. This means AST is 4 hours ahead of PST. When it's 8:00 AM in Los Angeles (PST), it's 12:00 PM in Halifax (AST). This is one of the largest time differences within North America.
How does the PST to AST offset compare to other North American conversions?
The 4-hour PST to AST difference is the largest coast-to-coast conversion in North America. PST to EST is 3 hours, PST to CST is 2 hours, and PST to MST is 1 hour. Atlantic Canada (AST) is the easternmost time zone, making it the furthest from Pacific time.
Which regions use Atlantic Standard Time?
Atlantic Standard Time (AST) is used in Atlantic Canada, including Nova Scotia, New Brunswick, Prince Edward Island, and parts of Newfoundland and Labrador. During daylight saving time (March to November), these regions observe Atlantic Daylight Time (ADT, UTC-3). Some Caribbean islands also use AST.
Does daylight saving time affect PST to AST conversion?
Both PST/PDT and AST/ADT observe daylight saving time on the same dates (second Sunday in March and first Sunday in November). During standard time (November to March), the difference is 4 hours (PST to AST). During daylight saving (March to November), the difference is also 4 hours (PDT to ADT).
What are the best times to schedule calls between PST and AST regions?
Business hour overlap is limited due to the 4-hour difference. Early morning in Pacific time (8-10 AM PST) aligns with afternoon in Atlantic Canada (12-2 PM AST). Afternoon hours (2-4 PM PST) overlap with early evening (6-8 PM AST). The Atlantic region typically starts and ends work hours about 4 hours earlier than Pacific time.
Why coordinate between Pacific and Atlantic Canada?
Many companies operate across North America with offices on both coasts. The Pacific region includes tech hubs (Vancouver, Seattle, San Francisco, Los Angeles), while Atlantic Canada has growing tech sectors (Halifax, Saint John) and strong ties to Europe. International trade, especially with Europe and Asia, requires coordination across all North American time zones.
Pro Tips
- • The 4-hour PST to AST difference is the largest coast-to-coast North American conversion. When planning meetings, remember that 8 AM PST is already noon AST - the start of afternoon in Halifax.
- • Early morning standups (8-9 AM PST) work well for Pacific teams to catch Atlantic region late mornings (12-1 PM AST). Both teams are typically fresh and focused during this window.
- • Afternoon meetings (2-3 PM PST) align with early evening (6-7 PM AST). For Atlantic region teams, this is late in the workday, so reserve this window for important decisions, not routine updates.
- • Use 10 AM PST (2 PM AST) as your "golden hour" for cross-coast meetings. It's mid-morning productivity time on the Pacific coast and early afternoon in Atlantic Canada.
- • Document all meeting times in both PST and AST to prevent confusion. The 4-hour difference is significant enough that timezone errors can cause serious scheduling issues.
- • When coordinating with international teams in Europe, remember that Atlantic Canada is much closer to European time (only 4-5 hours behind). Consider Atlantic region availability first for European coordination.
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