IST
India Standard Time
GMT +5:30
AST/ADT
Atlantic Standard Time
GMT -4
ADT automatically adjusted to AST time zone, that is in use

Time Difference

India Standard Time is 9 hours and 30 minutes ahead of Atlantic Standard Time
11:00 pm23:00 in IST is 1:30 pm13:30 in AST

IST to ADT call time
Best time for a conference call or a meeting is between 4:30pm-6:30pm in IST which corresponds to 8am-10am in ADT

11:00 pm23:00 India Standard Time (IST). Offset UTC +5:30 hours
1:30 pm13:30 Atlantic Standard Time (AST). Offset UTC -4:00 hours

11:00 pm23:00 IST / 1:30 pm13:30 AST

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

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

Atlantic Daylight Time

Offset: ADT is 3 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries: It is used in following countries: Bermuda, Canada, Greenland

Principal Cities: The largest city in the ADT timezone is Halifax from Canada with population about 359,111 people. Other major cities in the area are Sydney, Dartmouth, Saint John, Moncton

French: HAA - Heure Avancée de l'Atlantique

ADT Time Zone Geo Map
ADT timezone map

Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone, however during winter some places adjust time for one hour back and observe Atlantic Standard Time (AST).

Daylight saving time clock moves back for one hour from 2am to 1amEnd: Atlantic Daylight Time (ADT) has ended on Sunday, November 7, 2021 at 2:00 am local time and clocks were set one hour back to Sunday, November 7, 2021, 1:00 am local standard time instead. Daylight saving ends annually the on first Sunday of November

Daylight saving time clock moves forward for one hour from 2am to 3amStart: Atlantic Daylight Time (ADT) starts on Sunday, March 13, 2022 at 2:00 am local time and clocks are set one hour forward to Sunday, March 13, 2022, 3:00 am. Daylight saving starts annually the on second Sunday of March

ADT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -03 - basic short
  • -0300 - basic
  • -03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates three 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
  • Papa - Military abbreviation for ADT
  • P - short form of 'Papa'
IANA/Olson: Reflects ADT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Halifax
  • America/Moncton
  • America/Thule
  • Atlantic/Bermuda
  • Canada/Atlantic
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • WGT - West Greenland Time
  • AMST - Amazon Summer Time
  • ART - Argentina Time
  • BRT - Brasília time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • SRT - Suriname Time
  • UYT - Uruguay Time