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GST to AST Converter

GST
Gulf Standard Time
GMT +4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
AST
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

GST is 8 hours ahead of AST. GST uses GMT +4, and AST uses GMT -4 for this comparison.

For example, 4:00 pm GST is 8:00 am AST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 4:30pm-5:30pm GST, which is 8:30am-9:30am AST.

Compare GST time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Gulf Standard Time is 8 hours ahead of Atlantic Standard Time
4:00 pm16:00 in GST is 8:00 am08:00 in AST

GST to AST call time
Best time for a conference call or a meeting is between 4:30pm-5:30pm in GST which corresponds to 8:30am-9:30am in AST

4:00 pm16:00 Gulf Standard Time (GST). Offset UTC +4:00 hours
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

4:00 pm16:00 GST / 8:00 am08:00 AST

GSTAST
12am (midnight)4pm
1am5pm
2am6pm
3am7pm
4am8pm
5am9pm
6am10pm
7am11pm
8am12am (midnight)
9am1am
10am2am
11am3am
12pm (noon)4am
1pm5am
2pm6am
3pm7am
4pm8am
5pm9am
6pm10am
7pm11am
8pm12pm (noon)
9pm1pm
10pm2pm
11pm3pm
00:0016:00
01:0017:00
02:0018:00
03:0019:00
04:0020:00
05:0021:00
06:0022:00
07:0023:00
08:0000:00
09:0001:00
10:0002:00
11:0003:00
12:0004:00
13:0005:00
14:0006:00
15:0007:00
16:0008:00
17:0009:00
18:0010:00
19:0011:00
20:0012:00
21:0013:00
22:0014:00
23:0015:00

Gulf Standard Time

Offset: GST is 4 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: United Arab Emirates

Principal Cities: The largest city in the GST time zone is Dubai in United Arab Emirates, with about 1.137 million people. Other major cities in this time zone include Abu Dhabi, Sharjah, Al Ain, Ajman.

Daylight Saving: Clocks in Gulf Standard Time (GST) do not change for daylight saving time, so GST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

GST Time Zone Geo Map
GST timezone map

GST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +04 - basic short
  • +0400 - basic
  • +04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0400 - sign character (+) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Delta - Military abbreviation for GST
  • D - short form of 'Delta'
Time zones with the GMT +4 offset:
  • KUYT - Kuybyshev Time
  • MSD - Moscow Daylight Time
  • SAMT - Samara Time
  • AMT - Armenia Time
  • AZT - Azerbaijan Time
  • D - Delta Time Zone
  • GET - Georgia Standard Time
  • GST - Gulf Standard Time
  • MUT - Mauritius Time
  • RET - Reunion Time
  • SCT - Seychelles Time

Atlantic Standard Time

Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)

Principal Cities: The largest city in the AST time zone is Santo Domingo in Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax.

French: HNA - Heure Normale de l'Atlantique

Spanish: AST - Tiempo Estándar del Atlántico

AST Time Zone Geo Map
AST timezone map

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).

Daylight saving time clock moves back for one hour from 2am to 1amStart: Atlantic Standard Time (AST) started on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the first Sunday of November.

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Atlantic Standard Time (AST) ends on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.

AST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -04 - basic short
  • -0400 - basic
  • -04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Quebec - Military abbreviation for AST
  • Q - short form of 'Quebec'
IANA/Olson: Reflects AST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Anguilla
  • America/Antigua
  • America/Aruba
  • America/Barbados
  • America/Blanc-Sablon
  • America/Curacao
  • America/Dominica
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Grenada
  • America/Guadeloupe
  • America/Halifax
  • America/Kralendijk
  • America/Lower_Princes
  • America/Marigot
  • America/Martinique
  • America/Moncton
  • America/Montserrat
  • America/Port_of_Spain
  • America/Puerto_Rico
  • America/Santo_Domingo
  • America/St_Barthelemy
  • America/St_Kitts
  • America/St_Lucia
  • America/St_Thomas
  • America/St_Vincent
  • America/Thule
  • America/Tortola
  • America/Virgin
  • Atlantic/Bermuda
  • Canada/Atlantic
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
  • Atlantic Standard Time - UTC -4
  • Arabia Standard Time - UTC +3
Time zones with the GMT -4 offset:
  • AST - Atlantic Standard Time
  • EDT - Eastern Daylight Time
  • AMT - Amazon Time
  • BOT - Bolivia Time
  • CDT - Cuba Daylight Time
  • CLT - Chile Standard Time
  • FKT - Falkland Island Time
  • GYT - Guyana Time
  • HLV - Hora Legal de Venezuela
  • PYT - Paraguay Time
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT