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).

Dublin to Johannesburg

+1h

Dublin

ISTSOURCE

Ireland · UTC+01:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Johannesburg

SAST

South Africa · UTC+02:00

HH01

MM00

13:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Dublin

Johannesburg

12:00 AM

1:00 AM

2:00 AM

3:00 AM

4:00 AM

5:00 AM

6:00 AM

7:00 AM

8:00 AM

9:00 AM

10:00 AM

11:00 AM

12:00 PM

1:00 PM

2:00 PM

3:00 PM

4:00 PM

5:00 PM

6:00 PM

7:00 PM

8:00 PM

9:00 PM

10:00 PM

11:00 PM

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

IST and SAST on the World Map

The map below highlights the IST (Greenwich Mean Time) and SAST (South Africa Standard Time) timezone regions across the globe.

IST Zone

→

SAST Zone

Explore all world timezones interactively →

GMT – Greenwich Mean Time

UTC+00:00

Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.

Countries in GMT

United KingdomIrelandIcelandPortugal (mainland)GhanaSenegalMaliMauritaniaGambiaGuineaSierra LeoneLiberiaIvory CoastBurkina FasoMorocco (historically)

Major Cities in GMT

LondonDublinLisbonAccraReykjavikEdinburghCasablancaDakarBamakoAbidjanConakryFreetownMonrovia

Key Facts about GMT

•GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
•The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
•GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
•Iceland uses GMT year-round and never observes daylight saving time.
•The UK switches from GMT to BST (British Summer Time) in late March each year.

Daylight Saving:Yes – switches to BST

Learn more about GMT 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 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 →

Dublin vs Johannesburg: Offsets, DST and Best Call Times

Dublin runs on Irish Standard Time (IST) at UTC+01:00, currently observing daylight saving time. Johannesburg runs on South Africa Standard Time (SAST) at UTC+02:00. That puts Dublin 1 hour ahead of Johannesburg — a difference of +1h at the current offsets.

In practice, when it is 9:00 AM in Dublin it is 10:00 AM in Johannesburg. Midnight in Dublin is 1:00 AM in Johannesburg.Dublin observes daylight saving time while Johannesburg does not, so the gap narrows or widens by an hour part of the year.

Dublin to Johannesburg time conversion table

Dublin (IST)	Johannesburg (SAST)	Day
12:00 AM	1:00 AM	same day
6:00 AM	7:00 AM	same day
7:00 AM	8:00 AM	same day
8:00 AM	9:00 AM	same day
9:00 AM	10:00 AM	same day
12:00 PM	1:00 PM	same day
3:00 PM	4:00 PM	same day
5:00 PM	6:00 PM	same day
6:00 PM	7:00 PM	same day
9:00 PM	10:00 PM	same day

Why people convert Dublin to Johannesburg time

Scheduling a call from Dublin to Johannesburg: a 10:00 AM start in Dublin lands at 11:00 AM in Johannesburg, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Dublin and Johannesburg are inside the 9-to-5 working day between 9:00 AM and 4:00 PM IST time (10:00 AM–5:00 PM SAST). That is roughly 7 hours of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in Dublin is 9:00 PM in Johannesburg makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM IST" is unambiguous; "3 PM" across a +1h gap is not.
Block 9:00 AM–4:00 PM IST as the recurring meeting window if you work primarily from Dublin and need Johannesburg colleagues present.
Dublin: Clocks fall back on Sun, Oct 25, 2026. Re-check this page after that date because the offset changes and so does the +1h gap.

About GMT (Greenwich Mean Time)

Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.

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 Dublin and Johannesburg

Both Dublin and Johannesburg sit inside the 9 AM – 5 PM working day between 9:00 AM–4:00 PM IST, which is 10:00 AM–5:00 PM SAST. That gives roughly 7 hours of shared time — the safest window for a live call or meeting.

Business hours overlap

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

Dublin is 1 hour ahead of Johannesburg (IST UTC+01:00 → SAST UTC+02:00). The shared working window is 9:00 AM–4:00 PM IST. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

Dublin

☀ Currently in DST

Standard: UTC+00:00 · DST: UTC+01:00

Clocks fall back on Sun, Oct 25, 2026

Johannesburg

Does not observe DST

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 Dublin and Johannesburg?

Dublin (IST, UTC+01:00) is 1 hour ahead of Johannesburg (SAST, UTC+02:00). The gap is currently +1h.

How do I convert Dublin time to Johannesburg time?

Add +1h to Dublin local time. For example, 9:00 AM in Dublin is 10:00 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 offset from Dublin.

What is the best time to call Johannesburg from Dublin?

Call between 9:00 AM and 4:00 PM IST — that maps to 10:00 AM–5:00 PM SAST and keeps both parties inside the working day.

Which is ahead, Dublin or Johannesburg?

Dublin is 1 hour ahead of Johannesburg. When it is 12:00 PM in Dublin it is 1:00 PM in Johannesburg.

Do Dublin and Johannesburg use different time zones?

Dublin (Ireland) uses IST at UTC+01:00, while Johannesburg (South Africa) uses SAST at UTC+02:00. The IANA identifiers are Europe/Dublin and Africa/Johannesburg.

Does daylight saving time affect the Dublin–Johannesburg difference?

Yes at the moment: Dublin is on daylight saving time and Johannesburg is not, so the +1h gap shifts by an hour when exactly one of them changes clocks.

Which other cities share Dublin's time zone?

IST also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.

Which countries use IST, Dublin's zone?

IST is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.

Is there a day difference between Dublin and Johannesburg?

Not normally. The +1h gap only pushes the date over for late-evening times.

What is the time difference between Dublin and Johannesburg?

Johannesburg is +1h from Dublin.

What timezone is Dublin in?

Dublin operates on its local timezone.

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 Johannesburg?

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

Which countries use GMT (Greenwich Mean Time)?

GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.

Does GMT observe daylight saving time?

Yes, GMT switches to BST during summer months.

What are some interesting facts about GMT?

GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.