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).

Sydney to IRST

-6h 30m

Sydney

AESTSOURCE

Australia · UTC+10:00DST observed

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

IRST

UTC+03:30

HH05

MM30

05:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Sydney

IRST

12:00 AM

5:30 PM-1

2:00 AM

7:30 PM-1

4:00 AM

9:30 PM-1

6:00 AM

11:30 PM-1

8:00 AM

1:30 AM

10:00 AM

3:30 AM

12:00 PM

5:30 AM

2:00 PM

7:30 AM

4:00 PM

9:30 AM

6:00 PM

11:30 AM

8:00 PM

1:30 PM

10:00 PM

3:30 PM

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

AEST and IRST on the World Map

The map below highlights the AEST (Australian Eastern Standard Time) and IRST (Iran Standard Time) timezone regions across the globe.

AEST Zone

→

IRST Zone

Explore all world timezones interactively →

AEST – Australian Eastern Standard Time

UTC+10:00

Australian Eastern Standard Time (AEST) covers eastern Australia, 10 hours ahead of UTC.

Countries in AEST

Australia (NSW, VIC, QLD, TAS, ACT)Papua New Guinea

Major Cities in AEST

SydneyMelbourneBrisbaneCanberraHobartGold Coast

Key Facts about AEST

•Queensland does not observe daylight saving time, staying on AEST year-round.
•Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
•The Australian Securities Exchange (ASX) operates on AEST/AEDT.
•AEST is 15 hours ahead of EST during winter.

Daylight Saving:Yes – switches to AEDT

Learn more about AEST 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

About Sydney

Wikipedia

Sydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.

Population:5.4 million

Metro:5.4 million

Business Hours:9:00 AM - 5:00 PM AEST

Currency:AUD (A$)

Stock Exchange:ASX (Australian Securities Exchange)

Key Landmarks

Sydney Opera HouseSydney Harbour BridgeBondi BeachDarling HarbourRoyal Botanic Garden

Did You Know?

Sydney is one of the first major cities to welcome the New Year.

Learn more about AEST timezone →

Sydney vs IRST: Offsets, DST and Best Call Times

Sydney runs on Australian Eastern Standard Time (AEST) at UTC+10:00. IRST runs on Iran Standard Time (IRST) at UTC+03:30. That puts Sydney 6 hours 30 minutes behind IRST — a difference of -6h 30m at the current offsets.

In practice, when it is 9:00 AM in Sydney it is 2:30 AM in IRST. Midnight in Sydney is 5:30 PM in IRST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Sydney to IRST time conversion table

Sydney (AEST)	IRST (IRST)	Day
12:00 AM	5:30 PM	previous day
6:00 AM	11:30 PM	previous day
7:00 AM	12:30 AM	same day
8:00 AM	1:30 AM	same day
9:00 AM	2:30 AM	same day
12:00 PM	5:30 AM	same day
3:00 PM	8:30 AM	same day
5:00 PM	10:30 AM	same day
6:00 PM	11:30 AM	same day
9:00 PM	2:30 PM	same day

Why people convert Sydney to IRST time

Scheduling a call from Sydney to IRST: a 10:00 AM start in Sydney lands at 3:30 AM in IRST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Sydney and IRST are inside the 9-to-5 working day between 3:30 PM and 5:00 PM AEST time (9:00 AM–10:30 AM IRST). That is roughly 1 hours 30 minutes of usable overlap.
Coordinating a Sydney-based team with IRST contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.

Always state the zone abbreviation, not just the hour. "3:00 PM AEST" is unambiguous; "3 PM" across a -6h 30m gap is not.
Block 3:30 PM–5:00 PM AEST as the recurring meeting window if you work primarily from Sydney and need IRST colleagues present.
Sydney: Clocks spring forward on Sat, Oct 3, 2026. Re-check this page after that date because the offset changes and so does the -6h 30m gap.

About AEST (Australian Eastern Standard Time)

Australian Eastern Standard Time (AEST) is used in the eastern states of Australia including New South Wales, Victoria, Queensland, Tasmania, and the ACT. During summer (October to April), NSW, VIC, TAS, and ACT switch to Australian Eastern Daylight Time (AEDT, UTC+11:00), while Queensland remains on AEST year-round.

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 Sydney and IRST

Both Sydney and IRST sit inside the 9 AM – 5 PM working day between 3:30 PM–5:00 PM AEST, which is 9:00 AM–10:30 AM IRST. That gives roughly 1 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

Sydney and IRST overlap for only 90 minutes (3:30 PM–5:00 PM AEST), so meetings have to be booked precisely.

Sydney is 6 hours 30 minutes behind IRST (AEST UTC+10:00 → IRST UTC+03:30). The shared working window is 3:30 PM–5:00 PM AEST. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

Sydney

❄ Currently in Standard Time

Standard: UTC+10:00 · DST: UTC+11:00

Clocks spring forward on Sat, Oct 3, 2026

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 Sydney and IRST?

Sydney (AEST, UTC+10:00) is 6 hours 30 minutes behind IRST (IRST, UTC+03:30). The gap is currently -6h 30m.

How do I convert Sydney time to IRST time?

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

What is the best time to call IRST from Sydney?

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

Which is behind, Sydney or IRST?

Sydney is 6 hours 30 minutes behind IRST. When it is 12:00 PM in Sydney it is 5:30 AM in IRST.

Do Sydney and IRST use different time zones?

Sydney (Australia) uses AEST at UTC+10:00, while IRST uses IRST at UTC+03:30. The IANA identifiers are Australia/Sydney and Asia/Tehran.

Does daylight saving time affect the Sydney–IRST difference?

Neither zone observes daylight saving time, so the -6h 30m offset between Sydney and IRST is fixed all year.

Which other cities share Sydney's time zone?

AEST also covers Sydney, Melbourne, Brisbane, Canberra, Hobart, Gold Coast.

Which countries use AEST, Sydney's zone?

AEST is used in Australia (NSW, VIC, QLD, TAS, ACT), Papua New Guinea.

Is there a day difference between Sydney and IRST?

Not normally. The -6h 30m gap only pushes the date over the previous day.

What is the time difference between Sydney and IRST?

IRST is -6h 30m from Sydney.

What timezone is Sydney in?

Sydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.