AST
Atlantic Standard Time
GMT -4
IST
India Standard Time
GMT +5:30

Time Difference

Atlantic Standard Time is 9 hours and 30 minutes behind India Standard Time
12:00 am00:00 in AST is 9:30 am09:30 in IST

AST to IST call time
Best time for a conference call or a meeting is between 8am-10am in AST which corresponds to 5:30pm-7:30pm in IST

12:00 am00:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
9:30 am09:30 India Standard Time (IST). Offset UTC +5:30 hours

12:00 am00:00 AST / 9:30 am09:30 IST

AST IST
12am (midnight) 9:30 am
1am 10:30 am
2am 11:30 am
3am 12:30 pm
4am 1:30 pm
5am 2:30 pm
6am 3:30 pm
7am 4:30 pm
8am 5:30 pm
9am 6:30 pm
10am 7:30 pm
11am 8:30 pm
12pm (noon) 9:30 pm
1pm 10:30 pm
2pm 11:30 pm
3pm 12:30 am
4pm 1:30 am
5pm 2:30 am
6pm 3:30 am
7pm 4:30 am
8pm 5:30 am
9pm 6:30 am
10pm 7:30 am
11pm 8:30 am
0:00 9:30
1:00 10:30
2:00 11:30
3:00 12:30
4:00 13:30
5:00 14:30
6:00 15:30
7:00 16:30
8:00 17:30
9:00 18:30
10:00 19:30
11:00 20:30
12:00 21:30
13:00 22:30
14:00 23:30
15:00 0:30
16:00 1:30
17:00 2:30
18:00 3:30
19:00 4:30
20:00 5:30
21:00 6:30
22:00 7:30
23:00 8:30

Atlantic Standard Time

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

Countries: It is used in following countries: 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 timezone is Santo Domingo from Dominican Republic with population about 2.202 million people. Other major cities in the area are 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 timezone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect 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 6, 2022 at 2:00 am local time and clocks were set one hour back to Sunday, November 6, 2022, 1:00 am. Standard time starts annually the on 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 12, 2023 at 2:00 am local time and clocks are set one hour forward to Sunday, March 12, 2023, 3:00 am local daylight time instead. Standard time starts annually the on 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 four hour and zero minutes time differences 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
  • Argentina Standard Time - UTC -3
  • Arabian Standard Time - UTC +3
  • Apia Standard Time - UTC +13
  • Azores Summer Time - UTC +0
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

India Standard Time

Offset: IST is 5 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Asia

Countries: It is used in following countries: India

Principal Cities: The largest city in the IST timezone is Mumbai from India with population about 12.692 million people. Other major cities in the area are Delhi, Bangalore, Kolkata, Chennai

Daylight Saving: India Standard Time (IST) is not adjusted for daylight saving therefore IST remains the same through out the year. This means, unlike some time zones where the clock is set forward by one hour every summer and backward by one hour during winter to adjust for daylight saving, India Standard Time remains the same

IST Time Zone Geo Map
IST timezone map

IST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0530 - basic
  • +05:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0530 - sign character (+) followed by a four digit time providing hours (05) and minutes (30) of the offset. Indicates five hour and thirty minutes time differences to the east of the zero meridian.
IANA/Olson: Reflects IST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Calcutta
  • Asia/Kolkata
IST Abbreviation: Several time zones share IST abbreviation and it could refer to these time zones
  • India Standard Time - UTC +5:30
  • Irish Standard Time - UTC +1
  • Israel Standard Time - UTC +2
  • Iran Standard Time - UTC +3:30