Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

Tehran to Johannesburg

-1h 30m

Tehran

IRSTSOURCE

Iran · UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Johannesburg

SAST

South Africa · UTC+02:00

HH10

MM30

10:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Tehran

Johannesburg

12:00 AM

10:30 PM-1

2:00 AM

12:30 AM

4:00 AM

2:30 AM

6:00 AM

4:30 AM

8:00 AM

6:30 AM

10:00 AM

8:30 AM

12:00 PM

10:30 AM

2:00 PM

12:30 PM

4:00 PM

2:30 PM

6:00 PM

4:30 PM

8:00 PM

6:30 PM

10:00 PM

8:30 PM

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

IRST and SAST on the World Map

The map below highlights the IRST (Iran Standard Time) and SAST (South Africa Standard Time) timezone regions across the globe.

IRST Zone

→

SAST 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

SAST – South Africa Standard Time

UTC+02:00

South Africa Standard Time (SAST) is the time zone for South Africa and neighboring countries, 2 hours ahead of UTC.

Countries in SAST

South AfricaLesothoEswatini

Major Cities in SAST

JohannesburgCape TownDurbanPretoriaPort Elizabeth

Key Facts about SAST

•South Africa does not observe daylight saving time.
•SAST is the same offset as EET and Israel Standard Time.
•The Johannesburg Stock Exchange (JSE) is Africa's largest.

Daylight Saving:No – UTC+02:00 year-round

Learn more about SAST on Wikipedia

About Tehran

Wikipedia

Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.

Population:9.4 million

Metro:16.8 million

Business Hours:8:00 AM - 4:00 PM IRST

Currency:IRR (﷼)

Stock Exchange:TSE (Tehran Stock Exchange)

Key Landmarks

Azadi TowerGolestan PalaceGrand BazaarMilad TowerTabiat Bridge

Did You Know?

Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).

Learn more about IRST timezone →

About Johannesburg

Wikipedia

Johannesburg operates on South Africa Time (SAST), UTC+2. As Africa's largest economy hub and home to the JSE, Johannesburg drives African financial markets.

Population:5.8 million

Metro:10.5 million

Business Hours:8:00 AM - 5:00 PM SAST

Currency:ZAR (R)

Stock Exchange:JSE (Johannesburg Stock Exchange)

Key Landmarks

Apartheid MuseumConstitution HillGold Reef CityMaboneng PrecinctSoweto

Did You Know?

Johannesburg is built on the world's largest gold deposit.

Learn more about SAST timezone →

Understanding the -1h 30m Gap: Tehran vs Johannesburg

Tehran runs on Iran Standard Time (IRST) at UTC+03:30. Johannesburg runs on South Africa Standard Time (SAST) at UTC+02:00. That puts Tehran 1 hour 30 minutes behind Johannesburg — a difference of -1h 30m at the current offsets.

In practice, when it is 9:00 AM in Tehran it is 7:30 AM in Johannesburg. Midnight in Tehran is 10:30 PM in Johannesburg. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Tehran to Johannesburg time conversion table

Tehran (IRST)	Johannesburg (SAST)	Day
12:00 AM	10:30 PM	previous day
6:00 AM	4:30 AM	same day
7:00 AM	5:30 AM	same day
8:00 AM	6:30 AM	same day
9:00 AM	7:30 AM	same day
12:00 PM	10:30 AM	same day
3:00 PM	1:30 PM	same day
5:00 PM	3:30 PM	same day
6:00 PM	4:30 PM	same day
9:00 PM	7:30 PM	same day

Why people convert Tehran to Johannesburg time

Scheduling a call from Tehran to Johannesburg: a 10:00 AM start in Tehran lands at 8:30 AM in Johannesburg, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Tehran and Johannesburg are inside the 9-to-5 working day between 10:30 AM and 5:00 PM IRST time (9:00 AM–3:30 PM SAST). That is roughly 6 hours 30 minutes of usable overlap.
Booking travel or deliveries: tracking Johannesburg local time against Tehran keeps pickup windows and arrival estimates honest across the -1h 30m offset.

Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a -1h 30m gap is not.
Block 10:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from Tehran and need Johannesburg 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 SAST (South Africa Standard Time)

South Africa Standard Time (SAST) is used in South Africa, Lesotho, and Eswatini. SAST does not observe daylight saving time. Johannesburg and Cape Town are major economic hubs in Africa.

Best time to call between Tehran and Johannesburg

Both Tehran and Johannesburg sit inside the 9 AM – 5 PM working day between 10:30 AM–5:00 PM IRST, which is 9:00 AM–3:30 PM SAST. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

Tehran and Johannesburg share 6 hours of working-hours overlap (10:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.

Tehran is 1 hour 30 minutes behind Johannesburg (IRST UTC+03:30 → SAST UTC+02:00). The shared working window is 10:30 AM–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 Tehran and Johannesburg?

Tehran (IRST, UTC+03:30) is 1 hour 30 minutes behind Johannesburg (SAST, UTC+02:00). The gap is currently -1h 30m.

How do I convert Tehran time to Johannesburg time?

Add -1h 30m to Tehran local time. For example, 9:00 AM in Tehran is 7:30 AM in Johannesburg.

What time is it in Johannesburg right now?

Johannesburg uses SAST at UTC+02:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -1h 30m offset from Tehran.

What is the best time to call Johannesburg from Tehran?

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

Which is behind, Tehran or Johannesburg?

Tehran is 1 hour 30 minutes behind Johannesburg. When it is 12:00 PM in Tehran it is 10:30 AM in Johannesburg.

Do Tehran and Johannesburg use different time zones?

Tehran (Iran) uses IRST at UTC+03:30, while Johannesburg (South Africa) uses SAST at UTC+02:00. The IANA identifiers are Asia/Tehran and Africa/Johannesburg.

Does daylight saving time affect the Tehran–Johannesburg difference?

Neither zone observes daylight saving time, so the -1h 30m offset between Tehran and Johannesburg is fixed all year.

Which other cities share Tehran's time zone?

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

Which countries use IRST, Tehran's zone?

IRST is used in Iran.

Is there a day difference between Tehran and Johannesburg?

Not normally. The -1h 30m gap only pushes the date over the previous day.

What is the time difference between Tehran and Johannesburg?

Johannesburg is -1h 30m from Tehran.

What timezone is Tehran in?

Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.

What timezone is Johannesburg in?

Johannesburg operates on South Africa Time (SAST), UTC+2. As Africa's largest economy hub and home to the JSE, Johannesburg drives African financial markets.

What are the business hours in Tehran?

Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.

What are the business hours in Johannesburg?

Standard business hours in Johannesburg are 8:00 AM - 5:00 PM SAST.

What is the best time to schedule a call between Tehran and Johannesburg?

The best overlap for a call is when both cities are in business hours. Tehran works 8:00 AM - 4:00 PM IRST and Johannesburg works 8:00 AM - 5:00 PM SAST (-1h 30m difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Tehran and Johannesburg?

Tehran uses IRR (﷼) while Johannesburg uses ZAR (R). Check current exchange rates when planning travel or business between these cities.

How do Tehran and Johannesburg compare in size?

Tehran has a population of approximately 9.4 million (metro: 16.8 million), while Johannesburg has approximately 5.8 million (metro: 10.5 million).

What are the major landmarks in Tehran and Johannesburg?

Tehran is known for Azadi Tower, Golestan Palace, Grand Bazaar. Johannesburg is famous for Apartheid Museum, Constitution Hill, Gold Reef City.

Do Tehran and Johannesburg have stock exchanges?

Yes. Tehran has the TSE (Tehran Stock Exchange) and Johannesburg has the JSE (Johannesburg Stock Exchange). The -1h 30m time difference affects trading hour overlaps between these exchanges.