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.

CLT to IRST

+7h 30m

CLT

CLTSOURCE

UTC-03:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

IRST

UTC+03:30

HH07

MM30

19:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

CLT

IRST

12:00 AM

6:30 AM

2:00 AM

8:30 AM

4:00 AM

10:30 AM

6:00 AM

12:30 PM

8:00 AM

2:30 PM

10:00 AM

4:30 PM

12:00 PM

6:30 PM

2:00 PM

8:30 PM

4:00 PM

10:30 PM

6:00 PM

12:30 AM+1

8:00 PM

2:30 AM+1

10:00 PM

4:30 AM+1

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

CLT and IRST on the World Map

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

CLT Zone

→

IRST Zone

Explore all world timezones interactively →

CLT – Chile Standard Time

UTC-04:00

Chile Standard Time (CLT) is the time zone for continental Chile, 4 hours behind UTC.

Countries in CLT

Chile

Major Cities in CLT

SantiagoValparaísoConcepciónViña del MarAntofagasta

Key Facts about CLT

•Chile observes daylight saving time, switching to CLST (UTC-03:00) in summer.
•Santiago is the largest city in Chile with over 6 million in the metro area.
•Chile spans over 4,300 km from north to south but uses one timezone.

Daylight Saving:Yes – switches to CLST

Learn more about CLT on Wikipedia

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

Comparing Time Zones: CLT and IRST

CLT runs on Chile Standard Time (CLT) at UTC-04:00. IRST runs on Iran Standard Time (IRST) at UTC+03:30. That puts CLT 7 hours 30 minutes ahead of IRST — a difference of +7h 30m at the current offsets.

In practice, when it is 9:00 AM in CLT it is 4:30 PM in IRST. Midnight in CLT is 7:30 AM in IRST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

CLT to IRST time conversion table

CLT (CLT)	IRST (IRST)	Day
12:00 AM	7:30 AM	same day
6:00 AM	1:30 PM	same day
7:00 AM	2:30 PM	same day
8:00 AM	3:30 PM	same day
9:00 AM	4:30 PM	same day
12:00 PM	7:30 PM	same day
3:00 PM	10:30 PM	same day
5:00 PM	12:30 AM	next day
6:00 PM	1:30 AM	next day
9:00 PM	4:30 AM	next day

Why people convert CLT to IRST time

Scheduling a call from CLT to IRST: a 10:00 AM start in CLT lands at 5:30 PM in IRST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both CLT and IRST are inside the 9-to-5 working day between 9:00 AM and 9:30 AM CLT time (4:30 PM–5:00 PM IRST). That is roughly 0 hours 30 minutes of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in CLT is 3:30 AM in IRST makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM CLT" is unambiguous; "3 PM" across a +7h 30m gap is not.
Block 9:00 AM–9:30 AM CLT as the recurring meeting window if you work primarily from CLT and need IRST colleagues present.

About CLT (Chile Standard Time)

Chile Standard Time (CLT) is the standard time in Chile. During summer months (October to March), Chile switches to Chile Summer Time (CLST, UTC-03:00). Chile is the longest north-south country in the world.

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.

Best time to call between CLT and IRST

Both CLT and IRST sit inside the 9 AM – 5 PM working day between 9:00 AM–9:30 AM CLT, which is 4:30 PM–5:00 PM IRST. That gives roughly 0 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

CLT and IRST overlap for only 30 minutes (9:00 AM–9:30 AM CLT), so meetings have to be booked precisely.

CLT is 7 hours 30 minutes ahead of IRST (CLT UTC-04:00 → IRST UTC+03:30). The shared working window is 9:00 AM–9:30 AM CLT. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

CLT

☀ Currently in DST

Standard: UTC-04:00 · DST: UTC-03:00

Clocks fall back on Sun, Apr 4, 2027

IRST

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 CLT and IRST?

CLT (CLT, UTC-04:00) is 7 hours 30 minutes ahead of IRST (IRST, UTC+03:30). The gap is currently +7h 30m.

How do I convert CLT time to IRST time?

Add +7h 30m to CLT local time. For example, 9:00 AM in CLT is 4:30 PM in IRST.

What time is it in IRST right now?

IRST uses IRST at UTC+03:30. Use the live converter at the top of this page — it updates in real time and already accounts for the +7h 30m offset from CLT.

What is the best time to call IRST from CLT?

Call between 9:00 AM and 9:30 AM CLT — that maps to 4:30 PM–5:00 PM IRST and keeps both parties inside the working day.

Which is ahead, CLT or IRST?

CLT is 7 hours 30 minutes ahead of IRST. When it is 12:00 PM in CLT it is 7:30 PM in IRST.

Does daylight saving time affect the CLT–IRST difference?

Neither zone observes daylight saving time, so the +7h 30m offset between CLT and IRST is fixed all year.

Which other cities share CLT's time zone?

CLT also covers Santiago, Valparaíso, Concepción, Viña del Mar, Antofagasta.

Which countries use CLT, CLT's zone?

CLT is used in Chile.

Is there a day difference between CLT and IRST?

Not normally. The +7h 30m gap only pushes the date over for late-evening times.

What is the time difference between CLT and IRST?

IRST is +7h 30m from CLT.

What timezone is CLT in?

CLT operates on its local timezone.

What timezone is IRST in?

IRST operates on its local timezone.

Which countries use CLT (Chile Standard Time)?

CLT is used in Chile.

Does CLT observe daylight saving time?

Yes, CLT switches to CLST during summer months.

What are some interesting facts about CLT?

Chile observes daylight saving time, switching to CLST (UTC-03:00) in summer. Santiago is the largest city in Chile with over 6 million in the metro area.