GST to AST Converter

Convert time between Gulf Standard Time (GST) and Atlantic Standard Time (AST)

Gulf Standard Time (GST)

21:00:28
UTC +0
Mar 21, 2026
Asia/Dubai

Atlantic Standard Time (AST)

21:00:28
UTC +0
Mar 21, 2026
America/Halifax

Time Difference

Atlantic Standard Time (AST) is 0 hours ahead of Gulf Standard Time (GST)

Select Date

Select Time

Quick Reference

GSTAST
06:0023:00
08:0001:00
10:0003:00
12:0005:00
14:0007:00
16:0009:00
18:0011:00
20:0013:00
22:0015:00
00:0017:00
02:0019:00
04:0021:00

Top 10 Most Common Time Zones

AbbreviationFull NameUTC OffsetTypical Use
UTCCoordinated Universal TimeUTC ±0Global reference standard (servers, logs, APIs)
EST / EDTEastern (US) TimeUTC −5 / −4New York, Toronto — North American business hub
CST / CDTCentral (US) TimeUTC −6 / −5Chicago, Dallas — US central business region
PST / PDTPacific (US) TimeUTC −8 / −7San Francisco, Los Angeles — tech industry standard
GMT / BSTGreenwich Mean / British Summer TimeUTC 0 / +1UK, used globally as a reference with UTC
CET / CESTCentral European (Summer) TimeUTC +1 / +2Paris, Berlin, Amsterdam — EU business core
ISTIndia Standard TimeUTC +5:30India — major IT & outsourcing region
CSTChina Standard TimeUTC +8Beijing, Shanghai — East Asia business hub
JSTJapan Standard TimeUTC +9Tokyo — finance & tech hub
AEST / AEDTAustralian Eastern (Daylight) TimeUTC +10 / +11Sydney, 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 OffsetRegion(s)
CSTCentral Standard Time / China Standard Time / Cuba Standard TimeUTC−6 / UTC+8 / UTC−5North America, China, Cuba
ISTIndian Standard Time / Irish Standard Time / Israel Standard TimeUTC+5:30 / UTC+1 / UTC+2India, Ireland, Israel
ASTAtlantic Standard Time / Arabia Standard TimeUTC−4 / UTC+3Caribbean, Canada, Middle East
PSTPacific Standard Time / Philippine Standard TimeUTC−8 / UTC+8North America, Philippines
ESTEastern Standard Time (North America / Australia)UTC−5 / UTC+10North America, Australia

✅ Best Practice

To avoid ambiguity, always:

  • Use IANA tz identifiers — e.g., America/New_York instead of "EST"
  • Specify UTC offset explicitly — e.g., UTC−5 when abbreviations must be used
  • Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset

About GST to AST Time Conversion

Converting time between Gulf Standard Time (GST) and Atlantic Standard Time (AST) involves an 8-hour difference. GST is UTC+4 with no daylight saving time, while AST is UTC-4, observed in Atlantic Canada during winter months (roughly November to March). This places GST 8 hours ahead of AST. When Atlantic Canada transitions to Atlantic Daylight Time (ADT, UTC-3) in summer, the gap narrows to 7 hours.

This time zone converter uses the IANA timezone database for accurate results. Whether you're coordinating business between Dubai and Halifax, managing logistics between Gulf ports and Atlantic Canadian operations, or staying in touch with family across these regions, our converter ensures reliable time calculations throughout the year.

Common Use Cases for GST to AST Conversion

Business & Work

  • Scheduling end-of-day Gulf calls with Atlantic Canada offices to align with their morning hours
  • Coordinating trade and maritime logistics between Gulf ports and Atlantic Canadian harbours
  • Planning project meetings with teams in Halifax, Saint John, or Moncton

Personal & Travel

  • Staying connected with family and friends between the Gulf region and Atlantic Canada
  • Planning travel between UAE and Atlantic Canada with accurate layover and arrival timing
  • Scheduling virtual events and online meetups across the 8-hour time gap

Time Zone Information

Gulf Standard Time (GST)

  • UTC Offset: UTC+4 (no DST observed)
  • IANA Timezone: Asia/Dubai
  • Daylight Saving: Gulf Standard Time does not observe daylight saving time
  • Major Cities: Dubai, Abu Dhabi, Sharjah, Muscat, Ras Al Khaimah
  • Coverage: United Arab Emirates, Oman, and the broader Gulf region

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, Moncton, Fredericton, Charlottetown
  • Coverage: Atlantic Canada including Nova Scotia, New Brunswick, Prince Edward Island

Quick Reference: GST to AST

12:00 PM GST
4:00 AM AST
3:00 PM GST
7:00 AM AST
6:00 PM GST
10:00 AM AST
9:00 PM GST
1:00 PM AST

Remember: GST is 8 hours ahead of AST in winter. During Atlantic Canada's summer (ADT, UTC-3), the gap narrows to 7 hours.

Frequently Asked Questions

What is the time difference between GST and AST?

Gulf Standard Time (GST) is UTC+4, while Atlantic Standard Time (AST) is UTC-4. GST is 8 hours ahead of AST. When it's 6:00 PM in Dubai (GST), it's 10:00 AM in Halifax (AST). During Atlantic Canada's summer (ADT, UTC-3), the gap narrows to 7 hours.

Does Atlantic Standard Time observe daylight saving time?

Yes. Atlantic Canada transitions from AST (UTC-4) to Atlantic Daylight Time (ADT, UTC-3) on the second Sunday in March, and reverts to AST on the first Sunday in November. Since GST never changes, the offset between GST and Atlantic Canada is 8 hours during AST (winter) and 7 hours during ADT (summer). Always confirm which applies when scheduling meetings near transition dates.

Does Gulf Standard Time observe daylight saving time?

No. Gulf Standard Time (GST) is a fixed UTC+4 offset with no daylight saving time. The UAE and Oman remain on the same time year-round. Any variation in the gap between GST and Atlantic Canada is always caused by Atlantic Canada's seasonal clock shift, not the Gulf.

What are the best times to schedule calls between GST and AST?

With GST 8 hours ahead, the late Gulf workday aligns with the Atlantic Canada morning. A 5–7 PM GST window equals 9–11 AM AST in winter — ideal for catching Halifax at the start of its workday while Dubai wraps up. During ADT summer, 5 PM GST equals 10 AM ADT, still a great morning slot. Alternatively, 9 PM GST equals 1 PM AST — a practical afternoon window for Atlantic Canada.

Which regions use AST (Atlantic Standard Time)?

Atlantic Standard Time (UTC-4) is observed in winter across Atlantic Canada, including Nova Scotia (Halifax), New Brunswick (Saint John, Moncton, Fredericton), Prince Edward Island (Charlottetown), and parts of Labrador. Puerto Rico and the US Virgin Islands also use UTC-4 year-round. AST transitions to ADT (UTC-3) from the second Sunday in March to the first Sunday in November.

Which countries use GST (Gulf Standard Time)?

Gulf Standard Time (UTC+4) is used year-round by the United Arab Emirates (Dubai, Abu Dhabi, Sharjah) and Oman (Muscat). It is also shared by some Russian regions and parts of the Indian Ocean. In the Gulf context, GST specifically refers to the UAE and Oman time zone, which observes no daylight saving time.

Pro Tips

  • • GST is 8 hours ahead of AST in winter. A 6 PM GST end-of-day equals 10 AM AST — a natural morning start for Atlantic Canada colleagues.
  • • GST never changes. The gap shifts from 8 hours (AST winter) to 7 hours (ADT summer) solely because Atlantic Canada observes daylight saving time.
  • • During ADT season (March–November), a 5 PM GST call equals 10 AM ADT — giving even more comfortable morning overlap for both sides.
  • • A 9 PM GST evening message equals 1 PM AST — a useful asynchronous window if real-time calls are impractical.
  • • Puerto Rico and the US Virgin Islands share UTC-4 year-round (no DST). If your AST contact is there, the gap with GST is always exactly 8 hours.
  • • Set recurring GST–AST meeting invites in both time zones, and update them in March and November when Atlantic Canada clocks change.

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