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 São Paulo

-6h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

São Paulo

BRT

Brazil · UTC-03:00

HH05

MM30

05:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

São Paulo

12:00 AM

5:30 PM-1

2:00 AM

7:30 PM-1

4:00 AM

9:30 PM-1

6:00 AM

11:30 PM-1

8:00 AM

1:30 AM

10:00 AM

3:30 AM

12:00 PM

5:30 AM

2:00 PM

7:30 AM

4:00 PM

9:30 AM

6:00 PM

11:30 AM

8:00 PM

1:30 PM

10:00 PM

3:30 PM

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

IRST and BRT on the World Map

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

IRST Zone

→

BRT 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

BRT – Brasilia Time

UTC-03:00

Brasilia Time (BRT) is the time zone for eastern Brazil, 3 hours behind UTC.

Countries in BRT

Brazil (eastern)

Major Cities in BRT

São PauloRio de JaneiroBrasíliaBelo HorizonteSalvadorFortalezaRecifeCuritiba

Key Facts about BRT

•Brazil abolished daylight saving time in 2019.
•São Paulo is the largest city in the Southern Hemisphere.
•BRT is 2 hours ahead of EST.
•Brazil spans four different time zones.
•The B3 stock exchange in São Paulo operates on BRT.

Daylight Saving:No – UTC-03:00 year-round

Learn more about BRT on Wikipedia

About São Paulo

Wikipedia

São Paulo operates on Brasília Time (BRT), UTC-3. As South America's largest financial center, São Paulo's B3 exchange is the Americas' second-largest.

Population:12.4 million

Metro:22.4 million

Business Hours:9:00 AM - 6:00 PM BRT

Currency:BRL (R$)

Stock Exchange:B3 (Brasil Bolsa Balcão)

Key Landmarks

Paulista AvenueIbirapuera ParkSão Paulo CathedralMASPPinacoteca

Did You Know?

The city has more helicopters than any other city in the world due to traffic congestion.

Learn more about BRT timezone →

Comparing Time Zones: IRST and São Paulo

IRST runs on Iran Standard Time (IRST) at UTC+03:30. São Paulo runs on Brasilia Standard Time (BRT) at UTC-03:00. That puts IRST 6 hours 30 minutes behind São Paulo — a difference of -6h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 2:30 AM in São Paulo. Midnight in IRST is 5:30 PM in São Paulo. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to São Paulo time conversion table

IRST (IRST)	São Paulo (BRT)	Day
12:00 AM	5:30 PM	previous day
6:00 AM	11:30 PM	previous day
7:00 AM	12:30 AM	same day
8:00 AM	1:30 AM	same day
9:00 AM	2:30 AM	same day
12:00 PM	5:30 AM	same day
3:00 PM	8:30 AM	same day
5:00 PM	10:30 AM	same day
6:00 PM	11:30 AM	same day
9:00 PM	2:30 PM	same day

Why people convert IRST to São Paulo time

Scheduling a call from IRST to São Paulo: a 10:00 AM start in IRST lands at 3:30 AM in São Paulo, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and São Paulo are inside the 9-to-5 working day between 3:30 PM and 5:00 PM IRST time (9:00 AM–10:30 AM BRT). That is roughly 1 hours 30 minutes of usable overlap.
Booking travel or deliveries: tracking São Paulo local time against IRST keeps pickup windows and arrival estimates honest across the -6h 30m offset.

Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a -6h 30m gap is not.
Block 3:30 PM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need São Paulo 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 BRT (Brasilia Time)

Brasilia Time (BRT) is the standard time in the most populous regions of Brazil, including São Paulo, Rio de Janeiro, and the capital Brasília. Brazil abolished daylight saving time in 2019, so BRT is now observed year-round in these regions. Brazil spans four time zones in total.

Best time to call between IRST and São Paulo

Both IRST and São Paulo sit inside the 9 AM – 5 PM working day between 3:30 PM–5:00 PM IRST, which is 9:00 AM–10:30 AM BRT. That gives roughly 1 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and São Paulo overlap for only 90 minutes (3:30 PM–5:00 PM IRST), so meetings have to be booked precisely.

IRST is 6 hours 30 minutes behind São Paulo (IRST UTC+03:30 → BRT UTC-03:00). The shared working window is 3:30 PM–5:00 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 São Paulo?

IRST (IRST, UTC+03:30) is 6 hours 30 minutes behind São Paulo (BRT, UTC-03:00). The gap is currently -6h 30m.

How do I convert IRST time to São Paulo time?

Add -6h 30m to IRST local time. For example, 9:00 AM in IRST is 2:30 AM in São Paulo.

What time is it in São Paulo right now?

São Paulo uses BRT at UTC-03:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -6h 30m offset from IRST.

What is the best time to call São Paulo from IRST?

Call between 3:30 PM and 5:00 PM IRST — that maps to 9:00 AM–10:30 AM BRT and keeps both parties inside the working day.

Which is behind, IRST or São Paulo?

IRST is 6 hours 30 minutes behind São Paulo. When it is 12:00 PM in IRST it is 5:30 AM in São Paulo.

Do IRST and São Paulo use different time zones?

IRST uses IRST at UTC+03:30, while São Paulo (Brazil) uses BRT at UTC-03:00. The IANA identifiers are Asia/Tehran and America/Sao_Paulo.

Does daylight saving time affect the IRST–São Paulo difference?

Neither zone observes daylight saving time, so the -6h 30m offset between IRST and São Paulo is fixed all year.

Which other cities share IRST's time zone?

IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.

Which countries use IRST, IRST's zone?

IRST is used in Iran.

Is there a day difference between IRST and São Paulo?

Not normally. The -6h 30m gap only pushes the date over the previous day.

What is the time difference between IRST and São Paulo?

São Paulo is -6h 30m from IRST.

What timezone is IRST in?

IRST operates on its local timezone.

What timezone is São Paulo in?

São Paulo operates on Brasília Time (BRT), UTC-3. As South America's largest financial center, São Paulo's B3 exchange is the Americas' second-largest.