IST
India Standard Time
GMT +5:30
IRST
Iran Standard Time
GMT +3:30

Time Difference

India Standard Time is 2 hours ahead of Iran Standard Time
So 6:00 pm18:00 in IST is 4:00 pm16:00 in IRST

6:00 pm18:00 India Standard Time (IST). Offset UTC +5:30 hours
4:00 pm16:00 Iran Standard Time (IRST). Offset UTC +3:30 hours

6:00 pm18:00 IST / 4:00 pm16:00 IRST

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

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