AST to SGT Converter
Convert time between Atlantic Standard Time (AST) and Singapore Standard Time (SGT)
Atlantic Standard Time (AST)
Singapore Standard Time (SGT)
Time Difference
Singapore Standard Time (SGT) is 0 hours ahead of Atlantic Standard Time (AST)
Select Date
Select Time
Quick Reference
| AST | SGT |
|---|---|
| 23:00 | 10:00 |
| 01:00 | 12:00 |
| 03:00 | 14:00 |
| 05:00 | 16:00 |
| 07:00 | 18:00 |
| 09:00 | 20:00 |
| 11:00 | 22:00 |
| 13:00 | 00:00 |
| 15:00 | 02:00 |
| 17:00 | 04:00 |
| 19:00 | 06:00 |
| 21:00 | 08:00 |
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
About AST to SGT Time Conversion
Converting time between Atlantic Standard Time (AST) and Singapore Standard Time (SGT) bridges the western Atlantic and Southeast Asia. AST is UTC-4, while SGT is UTC+8 year-round, putting Singapore exactly 12 hours ahead of Atlantic time. The clean 12-hour offset makes the clock easy: just flip AM and PM, but verify the date.
This time zone converter uses the IANA timezone database to ensure accurate calculations. The Canadian Maritimes (Nova Scotia, New Brunswick, Prince Edward Island) observe AST in winter and switch to ADT (UTC-3) from March to November. Most Caribbean territories that use AST never switch, including Puerto Rico, the Dominican Republic and the US Virgin Islands. Whether you're scheduling Halifax-Singapore calls in winter or coordinating with Singaporean partners from year-round AST regions, our converter clarifies the math.
Common Use Cases for AST to SGT Conversion
Business & Work
- Scheduling winter calls between Halifax or Saint John and Singapore
- Coordinating with Singapore from year-round AST regions like Puerto Rico or the Dominican Republic
- Planning conference calls with Singapore partners from Maritime Canada during AST months
Personal & Travel
- Planning travel between the Canadian Maritimes or Caribbean and Singapore
- Coordinating with family and friends in Singapore
- Scheduling virtual events bridging the Atlantic and Asia
Time Zone Information
Atlantic Standard Time (AST)
- UTC Offset: UTC-4 (UTC-3 ADT in Maritime Canada during summer)
- IANA Timezone: America/Halifax
- Daylight Saving: Maritime Canada observes ADT from second Sunday in March to first Sunday in November; Caribbean AST regions usually stay on AST year-round
- Major Cities: Halifax, Saint John, Charlottetown, San Juan, Santo Domingo, Bridgetown
- Coverage: Canadian Maritime provinces, Bermuda, Puerto Rico, US Virgin Islands, Dominican Republic and most eastern Caribbean nations
Singapore Standard Time (SGT)
- UTC Offset: UTC+8
- IANA Timezone: Asia/Singapore
- Daylight Saving: No daylight saving time (consistent year-round)
- Major Cities: Singapore
- Coverage: Republic of Singapore
Quick Reference: AST to SGT
Remember: SGT is 12 hours ahead of AST. In Maritime Canada, summer ADT (UTC-3) shrinks the gap to 11 hours. Most Caribbean AST regions keep the 12-hour offset all year.
Frequently Asked Questions
What is the time difference between AST and SGT?
Atlantic Standard Time (AST) is UTC-4, while Singapore Standard Time (SGT) is UTC+8. SGT is 12 hours ahead of AST. When it is 12:00 PM in Halifax or San Juan, it is 12:00 AM the next day in Singapore.
Does AST stand for Atlantic or Arabia Standard Time?
On this site AST refers to Atlantic Standard Time (UTC-4), which covers the Canadian Maritimes, Bermuda, Puerto Rico and most of the eastern Caribbean. Arabia Standard Time is treated separately as a different timezone.
When does AST apply?
Maritime Canada is on AST from the first Sunday in November to the second Sunday in March; outside that window it switches to ADT (UTC-3) and the Singapore gap shrinks from 12 to 11 hours. Most Caribbean territories that use AST do not observe daylight saving, so AST applies year-round there.
What are the best times for AST-SGT business calls?
Late morning to midday in Halifax (10:00 AM to 12:00 PM AST) lines up with Singapore late evening (10:00 PM to 12:00 AM SGT). For a Singapore daytime contact, an early start in the Caribbean (5:00 to 8:00 AM AST) covers 5:00 to 8:00 PM SGT.
Which countries or regions use SGT?
Singapore Standard Time is used only in the Republic of Singapore. Neighboring Malaysia uses the same UTC+8 offset under the name MYT, and Western Australia uses AWST also at UTC+8.
Which countries or regions use AST?
Atlantic Standard Time covers the Canadian Maritime provinces, Bermuda, Puerto Rico, the US Virgin Islands, the Dominican Republic and most eastern Caribbean nations. Major cities include Halifax, Saint John, San Juan and Santo Domingo.
Pro Tips
- • SGT is 12 hours ahead of AST — flip AM and PM and roll the date forward by one day to get Singapore time.
- • Singapore never observes DST. All seasonal change comes from the Atlantic side.
- • In Maritime Canada, the offset shrinks to 11 hours during ADT (March to November). Confirm the Halifax date before scheduling.
- • Most Caribbean AST regions (Puerto Rico, Dominican Republic, US Virgin Islands) stay on AST year-round, so the 12-hour gap is steady.
- • For same-day overlap, an early Atlantic morning (6:00 to 9:00 AM AST) maps to a Singapore evening (6:00 to 9:00 PM SGT).
- • Use IANA identifiers America/Halifax and Asia/Singapore in calendars to handle the DST transition automatically.