Updating current time…
IST
12am
3am
6am
9am
12pm
3pm
6pm
9pm
BST
UTC+11
5h 30m ahead
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

5:30 pm17:30 IST (UTC+5:30), Oct 31, 2026 = 11:00 pm23:00 BST (UTC+11), Oct 31, 2026

IST is 5 hours and 30 minutes behind BST.

IST and BST examples

These examples always use IST (UTC+5:30) and BST (UTC+11). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

IST is 5 hours and 30 minutes behind BST.

How the time difference changes

IST is 5 hours and 30 minutes behind BST Pacific year-round.

Working hours of 9:00 am to 6:00 pm in IST correspond to 2:30 pm to 11:30 pm in BST Pacific.Working hours of 09:00 to 18:00 in IST correspond to 14:30 to 23:30 in BST Pacific.

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 behind Bougainville Standard Time.
5:30 pm17:30 in IST is 11:00 pm23:00 in BST

IST to BST call time
Best time for a conference call or a meeting is between 9am-12:30pm09:00-12:30 in IST which corresponds to 2:30pm-6pm14:30-18:00 in BST

5:30 pm17:30 India Standard Time (IST). Offset UTC +5:30 hours
11:00 pm23:00 Bougainville Standard Time (BST). Offset UTC +11:00 hours

5:30 pm17:30 IST / 11:00 pm23:00 BST

Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.

Hourly time comparison
ISTBST
5:30am
6:30am
7:30am
8:30am
9:30am
10:30am
11:30am
12:30pm
1:30pm
2:30pm
3:30pm
4:30pm
5:30pm
6:30pm
7:30pm
8:30pm
9:30pm
10:30pm
11:30pm
12:30am next day
1:30am next day
2:30am next day
3:30am next day
4:30am next day
05:30
06:30
07:30
08:30
09:30
10:30
11:30
12:30
13:30
14:30
15:30
16:30
17:30
18:30
19:30
20:30
21:30
22:30
23:30
00:30 next day
01:30 next day
02:30 next day
03:30 next day
04:30 next day

India Standard Time

Offset: IST is 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT).

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, Bengaluru, Hyderabad, Ahmedabad.

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; see upcoming clock changes worldwide.

Current time in India: India time now

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

Bougainville Standard Time

Offset: BST is 11 hours ahead of Greenwich Mean Time (GMT).

Countries using this time zone: Papua New Guinea

Principal Cities: The largest city in the BST time zone is Arawa in Papua New Guinea, with about 40,266 people. Other major cities in this time zone include Kieta, Panguna.

Daylight Saving: Clocks in Bougainville Standard Time (BST) do not change for daylight saving time, so BST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.

BST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +11 - basic short
  • +1100 - basic
  • +11:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +1100 - sign character (+) followed by a four digit time providing hours (11) and minutes (00) of the offset. Indicates an offset of eleven hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Lima - Military abbreviation for BST
  • L - short form of 'Lima'
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 +11 offset:
  • AEDT - Australian Eastern Daylight Time
  • BST - Bougainville Standard Time
  • KOST - Kosrae Time
  • L - Lima Time Zone
  • LHDT - Lord Howe Daylight Time
  • MAGT - Magadan Time
  • NCT - New Caledonia Time
  • NFT - Norfolk Time
  • PONT - Pohnpei Standard Time
  • SBT - Solomon Islands Time
  • VLAST - Vladivostok Summer Time
  • VUT - Vanuatu Time