IST
India Standard Time
GMT +5:30
12am
3am
6am
9am
12pm
3pm
6pm
9pm
GMT/BST
Greenwich Mean Time
GMT +0
12am
3am
6am
9am
12pm
3pm
6pm
9pm
BST is not used on this date
This converter uses GMT (GMT +0), the offset London uses on this date. Open the GMT converter.

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

Time Difference

India Standard Time is 5 hours and 30 minutes ahead of Greenwich Mean Time
5:30 pm17:30 in IST is 12:00 pm12:00 in GMT

IST to GMT call time
Best time for a conference call or a meeting is between 2:30pm-5pm in IST which corresponds to 9am-11:30am in GMT

5:30 pm17:30 India Standard Time (IST). Offset UTC +5:30 hours
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours

5:30 pm17:30 IST / 12:00 pm12:00 GMT

ISTGMT
12am (midnight)6:30 pm
1am7:30 pm
2am8:30 pm
3am9:30 pm
4am10:30 pm
5am11:30 pm
6am12:30 am
7am1:30 am
8am2:30 am
9am3:30 am
10am4:30 am
11am5:30 am
12pm (noon)6:30 am
1pm7:30 am
2pm8:30 am
3pm9:30 am
4pm10:30 am
5pm11:30 am
6pm12:30 pm
7pm1:30 pm
8pm2:30 pm
9pm3:30 pm
10pm4:30 pm
11pm5:30 pm
00:0018:30
01:0019:30
02:0020:30
03:0021:30
04:0022:30
05:0023:30
06:0000:30
07:0001:30
08:0002:30
09:0003:30
10:0004:30
11:0005:30
12:0006:30
13:0007:30
14:0008:30
15:0009:30
16:0010:30
17:0011:30
18:0012:30
19:0013:30
20:0014:30
21:0015:30
22:0016:30
23:0017:30

India Standard Time

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

Countries using this time zone: India

Principal Cities: The largest city in the IST time zone is Mumbai in India, with about 12.692 million people. Other major cities in this time zone include Delhi, Bangalore, Kolkata, Chennai.

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

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 an offset of five hours and thirty minutes 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

British Summer Time

Offset: BST is 1 hour ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Britain (UK), Guernsey, Isle of Man, Jersey

Principal Cities: The largest city in the BST time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Birmingham, Glasgow, Liverpool, Saint Helier.

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.

BST Time Zone Geo Map
BST timezone map

BST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +01 - basic short
  • +0100 - basic
  • +01:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0100 - sign character (+) followed by a four digit time providing hours (01) and minutes (00) of the offset. Indicates an offset of one hour to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Alpha - Military abbreviation for BST
  • A - short form of 'Alpha'
IANA/Olson: Reflects BST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Europe/Belfast
  • Europe/Guernsey
  • Europe/Isle_of_Man
  • Europe/Jersey
  • Europe/London
  • GB
  • GB-Eire
BST Abbreviation: Several time zones share BST abbreviation and it could refer to these time zones
  • British Summer Time - UTC +1
  • Bangladesh Standard Time - UTC +6
  • Bougainville Standard Time - UTC +11
Time zones with the GMT +1 offset:
  • BST - British Summer Time
  • CET - Central European Time
  • IST - Irish Standard Time
  • WEST - Western European Summer Time
  • A - Alpha Time Zone
  • CET - Central European Time
  • MEZ - Mitteleuropäische Zeit
  • WAT - West Africa Time
  • WST - Western Sahara Summer Time
  • BMT - Biel Mean Time