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 PST

-11h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

PST

UTC-07:00☀ DST active

HH12

MM30

00:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

PST

12:00 AM

1:30 PM-1

2:00 AM

3:30 PM-1

4:00 AM

5:30 PM-1

6:00 AM

7:30 PM-1

8:00 AM

9:30 PM-1

10:00 AM

11:30 PM-1

12:00 PM

1:30 AM

2:00 PM

3:30 AM

4:00 PM

5:30 AM

6:00 PM

7:30 AM

8:00 PM

9:30 AM

10:00 PM

11:30 AM

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

IRST and PST on the World Map

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

IRST Zone

→

PST 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

PST – Pacific Standard Time

UTC-08:00

Pacific Standard Time (PST) is the time zone for the US and Canadian Pacific coast, 8 hours behind UTC.

Countries in PST

United States (Pacific)Canada (British Columbia)Mexico (Baja California)

Major Cities in PST

Los AngelesSan FranciscoSeattleVancouverSan DiegoPortlandLas VegasSacramentoSan JoseTijuana

Key Facts about PST

•Silicon Valley and the world's biggest tech companies operate on Pacific Time.
•The Hollywood film industry runs on PST/PDT.
•PST is 3 hours behind EST, creating a significant business hours gap.
•Vancouver, Canada's third-largest city, uses PST.

Daylight Saving:Yes – switches to PDT

Learn more about PST on Wikipedia

Comparing Time Zones: IRST and PST

IRST runs on Iran Standard Time (IRST) at UTC+03:30. PST runs on Pacific Standard Time (PST) at UTC-08:00. That puts IRST 11 hours 30 minutes behind PST — a difference of -11h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 9:30 PM in PST on the previous day. Midnight in IRST is 12:30 PM in PST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to PST time conversion table

IRST (IRST)	PST (PST)	Day
12:00 AM	12:30 PM	previous day
6:00 AM	6:30 PM	previous day
7:00 AM	7:30 PM	previous day
8:00 AM	8:30 PM	previous day
9:00 AM	9:30 PM	previous day
12:00 PM	12:30 AM	same day
3:00 PM	3:30 AM	same day
5:00 PM	5:30 AM	same day
6:00 PM	6:30 AM	same day
9:00 PM	9:30 AM	same day

Why people convert IRST to PST time

Scheduling a call from IRST to PST: a 10:00 AM start in IRST lands at 10:30 PM in PST the previous day, so you can confirm the slot without doing the arithmetic yourself.
Handling a -11h 30m gap: IRST and PST have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in PST is 9:30 PM in IRST.
Watching a live event or market open: IRST viewers need 9:30 PM in PST to catch a 9:00 AM start there, and 11:30 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 -11h 30m gap is not.
With a -11h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week IRST takes the early slot, the next week PST does.

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 PST (Pacific Standard Time)

Pacific Standard Time (PST) covers the west coast of North America, including tech hubs like San Francisco and Seattle, and entertainment capital Los Angeles. The Pacific Time Zone is home to Silicon Valley and the world's largest technology companies. During summer, clocks advance to Pacific Daylight Time (PDT, UTC-07:00). PST is also observed in Baja California, Mexico.

Best time to call between IRST and PST

With a -11h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. PST opens at 9:00 AM PST, which is 9:30 PM in IRST, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

IRST and PST have no shared working hours because of the -11h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.

IRST is 11 hours 30 minutes behind PST (IRST UTC+03:30 → PST UTC-08:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

IRST

Does not observe DST

PST

☀ Currently in DST

Standard: UTC-08:00 · DST: UTC-07:00

Clocks fall back on Sun, Nov 1, 2026

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 PST?

IRST (IRST, UTC+03:30) is 11 hours 30 minutes behind PST (PST, UTC-08:00). The gap is currently -11h 30m.

How do I convert IRST time to PST time?

Add -11h 30m to IRST local time. For example, 9:00 AM in IRST is 9:30 PM in PST (previous day).

What time is it in PST right now?

PST uses PST at UTC-08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -11h 30m offset from IRST.