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.

IRST to SGT

+4h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

SGT

UTC+08:00

HH04

MM30

16:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

SGT

12:00 AM

4:30 AM

2:00 AM

6:30 AM

4:00 AM

8:30 AM

6:00 AM

10:30 AM

8:00 AM

12:30 PM

10:00 AM

2:30 PM

12:00 PM

4:30 PM

2:00 PM

6:30 PM

4:00 PM

8:30 PM

6:00 PM

10:30 PM

8:00 PM

12:30 AM+1

10:00 PM

2:30 AM+1

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

IRST and SGT on the World Map

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

IRST Zone

→

SGT 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

SGT – Singapore Standard Time

UTC+08:00

Singapore Standard Time (SGT) is the time zone for Singapore, 8 hours ahead of UTC.

Countries in SGT

Singapore

Major Cities in SGT

Singapore

Key Facts about SGT

•Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00).
•Singapore does not observe daylight saving time.
•The Singapore Exchange (SGX) operates on SGT.

Daylight Saving:No – UTC+08:00 year-round

Learn more about SGT on Wikipedia

Understanding the +4h 30m Gap: IRST vs SGT

IRST runs on Iran Standard Time (IRST) at UTC+03:30. SGT runs on Singapore Standard Time (SGT) at UTC+08:00. That puts IRST 4 hours 30 minutes ahead of SGT — a difference of +4h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 1:30 PM in SGT. Midnight in IRST is 4:30 AM in SGT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to SGT time conversion table

IRST (IRST)	SGT (SGT)	Day
12:00 AM	4:30 AM	same day
6:00 AM	10:30 AM	same day
7:00 AM	11:30 AM	same day
8:00 AM	12:30 PM	same day
9:00 AM	1:30 PM	same day
12:00 PM	4:30 PM	same day
3:00 PM	7:30 PM	same day
5:00 PM	9:30 PM	same day
6:00 PM	10:30 PM	same day
9:00 PM	1:30 AM	next day

Why people convert IRST to SGT time

Scheduling a call from IRST to SGT: a 10:00 AM start in IRST lands at 2:30 PM in SGT, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and SGT are inside the 9-to-5 working day between 9:00 AM and 12:30 PM IRST time (1:30 PM–5:00 PM SGT). That is roughly 3 hours 30 minutes of usable overlap.
Watching a live event or market open: IRST viewers need 1:30 PM in SGT to catch a 9:00 AM start there, and 7:30 PM 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 +4h 30m gap is not.
Block 9:00 AM–12:30 PM IRST as the recurring meeting window if you work primarily from IRST and need SGT 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 SGT (Singapore Standard Time)

Singapore Standard Time (SGT) is used in Singapore year-round. Singapore does not observe daylight saving time. Despite being geographically close to the UTC+07:00 zone, Singapore uses UTC+08:00 to align with major trading partners like China, Hong Kong, and Malaysia. Singapore is a major global financial hub.

Best time to call between IRST and SGT

Both IRST and SGT sit inside the 9 AM – 5 PM working day between 9:00 AM–12:30 PM IRST, which is 1:30 PM–5:00 PM SGT. That gives roughly 3 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and SGT overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.

IRST is 4 hours 30 minutes ahead of SGT (IRST UTC+03:30 → SGT UTC+08:00). The shared working window is 9:00 AM–12:30 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 SGT?

IRST (IRST, UTC+03:30) is 4 hours 30 minutes ahead of SGT (SGT, UTC+08:00). The gap is currently +4h 30m.

How do I convert IRST time to SGT time?

Add +4h 30m to IRST local time. For example, 9:00 AM in IRST is 1:30 PM in SGT.

What time is it in SGT right now?

SGT uses SGT at UTC+08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +4h 30m offset from IRST.