Does it handle Daylight Saving Time?

Yes, the tool automatically adjusts for Daylight Saving Time based on the specific date you select, ensuring accurate conversions year-round.

Can I add multiple cities?

Yes, you can add as many cities as you need to the dashboard to compare times across your entire global network simultaneously.

IRST to GST

+0h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

GST

UTC+04:00

HH12

MM30

12:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

GST

12:00 AM

12:30 AM

2:00 AM

2:30 AM

4:00 AM

4:30 AM

6:00 AM

6:30 AM

8:00 AM

8:30 AM

10:00 AM

10:30 AM

12:00 PM

12:30 PM

2:00 PM

2:30 PM

4:00 PM

4:30 PM

6:00 PM

6:30 PM

8:00 PM

8:30 PM

10:00 PM

10:30 PM

Green rows indicate typical business hours (9 AM - 5 PM)

IRST and GST on the World Map

The map below highlights the IRST (Iran Standard Time) and GST (Gulf Standard Time) timezone regions across the globe.

IRST Zone

→

GST Zone

Explore all world timezones interactively →

IRST – Iran Standard Time

UTC+03:30

Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.

Countries in IRST

Iran

Major Cities in IRST

TehranIsfahanMashhadTabrizShirazKaraj

Key Facts about IRST

•IRST is one of only a few time zones with a 30-minute offset.
•Iran observes daylight saving time, switching to IRDT (UTC+04:30).
•Tehran has a metropolitan population of over 16 million.

Daylight Saving:Yes – switches to IRDT

Learn more about IRST on Wikipedia

GST – Gulf Standard Time

UTC+04:00

Gulf Standard Time (GST) is used in the UAE, Oman, and other Gulf states, 4 hours ahead of UTC.

Countries in GST

UAEOmanGeorgiaAzerbaijanMauritius

Major Cities in GST

DubaiAbu DhabiMuscatBakuTbilisi

Key Facts about GST

•Dubai uses GST year-round with no daylight saving time.
•GST is 9 hours ahead of EST and 4 hours ahead of GMT.
•The Dubai Financial Market (DFM) operates on GST.

Daylight Saving:No – UTC+04:00 year-round

Learn more about GST on Wikipedia

Understanding the +0h 30m Gap: IRST vs GST

IRST runs on Iran Standard Time (IRST) at UTC+03:30. GST runs on Gulf Standard Time (GST) at UTC+04:00. That puts IRST 30 minutes ahead of GST — a difference of +0h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 9:30 AM in GST. Midnight in IRST is 12:30 AM in GST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to GST time conversion table

IRST (IRST)	GST (GST)	Day
12:00 AM	12:30 AM	same day
6:00 AM	6:30 AM	same day
7:00 AM	7:30 AM	same day
8:00 AM	8:30 AM	same day
9:00 AM	9:30 AM	same day
12:00 PM	12:30 PM	same day
3:00 PM	3:30 PM	same day
5:00 PM	5:30 PM	same day
6:00 PM	6:30 PM	same day
9:00 PM	9:30 PM	same day

Why people convert IRST to GST time

Scheduling a call from IRST to GST: a 10:00 AM start in IRST lands at 10:30 AM in GST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and GST are inside the 9-to-5 working day between 9:00 AM and 4:30 PM IRST time (9:30 AM–5:00 PM GST). That is roughly 7 hours 30 minutes of usable overlap.
Watching a live event or market open: IRST viewers need 9:30 AM in GST to catch a 9:00 AM start there, and 11:30 PM if the event is anchored to IRST.

Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a +0h 30m gap is not.
Block 9:00 AM–4:30 PM IRST as the recurring meeting window if you work primarily from IRST and need GST colleagues present.

About IRST (Iran Standard Time)

Iran Standard Time (IRST) is one of the few time zones with a 30-minute offset. Iran observes daylight saving time (IRDT, UTC+04:30) from late March to late September. Tehran, the capital, is one of the largest cities in the Middle East.

About GST (Gulf Standard Time)

Gulf Standard Time (GST) is the time zone used in the United Arab Emirates, Oman, and other Gulf states. GST does not observe daylight saving time. Dubai and Abu Dhabi, major international business and tourism hubs, operate on GST.

Best time to call between IRST and GST

Both IRST and GST sit inside the 9 AM – 5 PM working day between 9:00 AM–4:30 PM IRST, which is 9:30 AM–5:00 PM GST. That gives roughly 7 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and GST share 7 hours of working-hours overlap (9:00 AM–4:30 PM IRST), so scheduling a live meeting is straightforward.

IRST is 30 minutes ahead of GST (IRST UTC+03:30 → GST UTC+04:00). The shared working window is 9:00 AM–4:30 PM IRST. Remember to re-check around daylight-saving transitions.

Learn More About Time

Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between IRST and GST?

IRST (IRST, UTC+03:30) is 30 minutes ahead of GST (GST, UTC+04:00). The gap is currently +0h 30m.

How do I convert IRST time to GST time?

Add +0h 30m to IRST local time. For example, 9:00 AM in IRST is 9:30 AM in GST.

What time is it in GST right now?

GST uses GST at UTC+04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +0h 30m offset from IRST.