Updating current time…
IST
12am
3am
6am
9am
12pm
3pm
6pm
9pm
Z
UTC+0
5h 30m behind
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

5:30 pm17:30 IST (UTC+5:30), Oct 18, 2026 = 12:00 pm12:00 Z (UTC+0), Oct 18, 2026

IST is 5 hours and 30 minutes ahead of Z.

IST and Z examples

These examples always use IST (UTC+5:30) and Z (UTC+0). 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 ahead of Z.

How the time difference changes

IST is 5 hours and 30 minutes ahead of Z year-round.

Working hours of 9:00 am to 6:00 pm in IST correspond to 3:30 am to 12:30 pm in Z.Working hours of 09:00 to 18:00 in IST correspond to 03:30 to 12:30 in Z.

Compare IST time with Z 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 Zulu Time Zone.
5:30 pm17:30 in IST is 12:00 pm12:00 in Z

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

5:30 pm17:30 India Standard Time (IST). Offset UTC +5:30 hours
12:00 pm12:00 Zulu Time Zone (Z). Offset UTC 0:00 hours

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

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Hourly time comparison
ISTZ
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18:30 previous day
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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

Zulu Time Zone

Offset: Z is the same as Greenwich Mean Time (GMT).

Countries using this time zone: Antarctica, Burkina Faso, Faroe Islands, Gambia, Ghana, Greenland, Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Morocco, Portugal, Saint Helena, São Tomé and Príncipe, Senegal, Sierra Leone, Spain, Togo, United Kingdom, Western Sahara

Principal Cities: The largest city in the Z time zone is London in the United Kingdom, with about 8.962 million people. Other major cities in this time zone include Abidjan, Bamako, Casablanca, Dakar.

Coordinated Universal Time (UTC) is the world time standard that regulates clocks and time. It is the successor to Greenwich Mean Time (GMT). For casual use, UTC is the same as GMT, but UTC is the standard the scientific community uses.
UTC has been the time standard commonly used across the world since 1972. It is used in many technical fields, such as aviation and meteorology, and to synchronize time across internet networks.

Map of the areas on Zulu Time Zone (Z)
Z all year Z part of the year

Today some of the lighter areas are on UTC+1 (British Summer Time, Irish Standard Time, WEST).

Z representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
  • +00 - basic short
  • +0000 - basic
  • +00:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Zulu - Military abbreviation for Z
  • Z - short form of 'Zulu'
Time zones with the GMT +0 offset:
  • EGST - Eastern Greenland Summer Time
  • GMT - Greenwich Mean Time
  • WET - Western European Time
  • AZOST - Azores Summer Time
  • UTC - Coordinated Universal Time
  • WT - Western Sahara Standard Time
  • Z - Zulu Time Zone