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).

IRST to Lagos

-2h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Lagos

WAT

Nigeria · UTC+01:00

HH09

MM30

09:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

Lagos

12:00 AM

9:30 PM-1

2:00 AM

11:30 PM-1

4:00 AM

1:30 AM

6:00 AM

3:30 AM

8:00 AM

5:30 AM

10:00 AM

7:30 AM

12:00 PM

9:30 AM

2:00 PM

11:30 AM

4:00 PM

1:30 PM

6:00 PM

3:30 PM

8:00 PM

5:30 PM

10:00 PM

7:30 PM

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

IRST and WAT on the World Map

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

IRST Zone

→

WAT 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

WAT – West Africa Time

UTC+01:00

West Africa Time (WAT) is the time zone for West and Central Africa, 1 hour ahead of UTC.

Countries in WAT

NigeriaCameroonChadCongoAngolaNigerGabonEquatorial Guinea

Major Cities in WAT

LagosAbujaDoualaYaoundéLuandaKinshasaBrazzaville

Key Facts about WAT

•Lagos, Nigeria is the most populous city in Africa.
•WAT is the same offset as CET (UTC+01:00).
•Nigeria does not observe daylight saving time.

Daylight Saving:No – UTC+01:00 year-round

Learn more about WAT on Wikipedia

About Lagos

Wikipedia

Lagos operates on West Africa Time (WAT), UTC+1. As Africa's largest city and Nigeria's economic hub, Lagos is the center of African fintech innovation.

Population:15.4 million

Metro:21.3 million

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

Currency:NGN (₦)

Stock Exchange:NGX (Nigerian Exchange)

Key Landmarks

Nike Art GalleryLekki Conservation CentreNational MuseumTarkwa Bay BeachFreedom Park

Did You Know?

Lagos is one of the fastest-growing cities in the world and Africa's largest city.

Learn more about WAT timezone →

Understanding the -2h 30m Gap: IRST vs Lagos

IRST runs on Iran Standard Time (IRST) at UTC+03:30. Lagos runs on West Africa Time (WAT) at UTC+01:00. That puts IRST 2 hours 30 minutes behind Lagos — a difference of -2h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 6:30 AM in Lagos. Midnight in IRST is 9:30 PM in Lagos. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to Lagos time conversion table

IRST (IRST)	Lagos (WAT)	Day
12:00 AM	9:30 PM	previous day
6:00 AM	3:30 AM	same day
7:00 AM	4:30 AM	same day
8:00 AM	5:30 AM	same day
9:00 AM	6:30 AM	same day
12:00 PM	9:30 AM	same day
3:00 PM	12:30 PM	same day
5:00 PM	2:30 PM	same day
6:00 PM	3:30 PM	same day
9:00 PM	6:30 PM	same day

Why people convert IRST to Lagos time

Scheduling a call from IRST to Lagos: a 10:00 AM start in IRST lands at 7:30 AM in Lagos, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and Lagos are inside the 9-to-5 working day between 11:30 AM and 5:00 PM IRST time (9:00 AM–2:30 PM WAT). That is roughly 5 hours 30 minutes of usable overlap.
Watching a live event or market open: IRST viewers need 6:30 AM in Lagos to catch a 9:00 AM start there, and 2:30 AM 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 -2h 30m gap is not.
Block 11:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need Lagos 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 WAT (West Africa Time)

West Africa Time (WAT) is used across much of West and Central Africa, including Nigeria, the most populous country in Africa. WAT does not observe daylight saving time and shares the same offset as Central European Time (CET).

Best time to call between IRST and Lagos

Both IRST and Lagos sit inside the 9 AM – 5 PM working day between 11:30 AM–5:00 PM IRST, which is 9:00 AM–2:30 PM WAT. That gives roughly 5 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and Lagos share 5 hours of working-hours overlap (11:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.

IRST is 2 hours 30 minutes behind Lagos (IRST UTC+03:30 → WAT UTC+01:00). The shared working window is 11:30 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 IRST and Lagos?

IRST (IRST, UTC+03:30) is 2 hours 30 minutes behind Lagos (WAT, UTC+01:00). The gap is currently -2h 30m.

How do I convert IRST time to Lagos time?

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

What time is it in Lagos right now?

Lagos uses WAT at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -2h 30m offset from IRST.

What is the best time to call Lagos from IRST?

Call between 11:30 AM and 5:00 PM IRST — that maps to 9:00 AM–2:30 PM WAT and keeps both parties inside the working day.

Which is behind, IRST or Lagos?

IRST is 2 hours 30 minutes behind Lagos. When it is 12:00 PM in IRST it is 9:30 AM in Lagos.

Do IRST and Lagos use different time zones?

IRST uses IRST at UTC+03:30, while Lagos (Nigeria) uses WAT at UTC+01:00. The IANA identifiers are Asia/Tehran and Africa/Lagos.

Does daylight saving time affect the IRST–Lagos difference?

Neither zone observes daylight saving time, so the -2h 30m offset between IRST and Lagos 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 Lagos?

Not normally. The -2h 30m gap only pushes the date over the previous day.

What is the time difference between IRST and Lagos?

Lagos is -2h 30m from IRST.

What timezone is IRST in?

IRST operates on its local timezone.

What timezone is Lagos in?

Lagos operates on West Africa Time (WAT), UTC+1. As Africa's largest city and Nigeria's economic hub, Lagos is the center of African fintech innovation.