IRST to Singapore
+4h 30mIRST
IRSTSOURCESingapore
SGTGreen 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 – Iran Standard Time
UTC+03:30Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.
- •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.
SGT – Singapore Standard Time
UTC+08:00Singapore Standard Time (SGT) is the time zone for Singapore, 8 hours ahead of UTC.
- •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.
About Singapore
WikipediaSingapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.
The city-state has the world's highest percentage of millionaires, with 1 in 6 households.
Understanding the +4h 30m Gap: IRST vs Singapore
IRST runs on Iran Standard Time (IRST) at UTC+03:30. Singapore runs on Singapore Standard Time (SGT) at UTC+08:00. That puts IRST 4 hours 30 minutes ahead of Singapore — 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 Singapore. Midnight in IRST is 4:30 AM in Singapore. Neither zone observes daylight saving time, so the offset between them stays constant all year.
IRST to Singapore time conversion table
| IRST (IRST) | Singapore (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 Singapore time
- Scheduling a call from IRST to Singapore: a 10:00 AM start in IRST lands at 2:30 PM in Singapore, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both IRST and Singapore 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 Singapore 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 Singapore 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 Singapore
Both IRST and Singapore 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 Singapore 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 Singapore (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:
Frequently Asked Questions
What is the time difference between IRST and Singapore?
IRST (IRST, UTC+03:30) is 4 hours 30 minutes ahead of Singapore (SGT, UTC+08:00). The gap is currently +4h 30m.
How do I convert IRST time to Singapore time?
Add +4h 30m to IRST local time. For example, 9:00 AM in IRST is 1:30 PM in Singapore.
What time is it in Singapore right now?
Singapore 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.
What is the best time to call Singapore from IRST?
Call between 9:00 AM and 12:30 PM IRST — that maps to 1:30 PM–5:00 PM SGT and keeps both parties inside the working day.
Which is ahead, IRST or Singapore?
IRST is 4 hours 30 minutes ahead of Singapore. When it is 12:00 PM in IRST it is 4:30 PM in Singapore.
Do IRST and Singapore use different time zones?
IRST uses IRST at UTC+03:30, while Singapore (Singapore) uses SGT at UTC+08:00. The IANA identifiers are Asia/Tehran and Asia/Singapore.
Does daylight saving time affect the IRST–Singapore difference?
Neither zone observes daylight saving time, so the +4h 30m offset between IRST and Singapore 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 Singapore?
Not normally. The +4h 30m gap only pushes the date over for late-evening times.
What is the time difference between IRST and Singapore?
Singapore is +4h 30m from IRST.
What timezone is IRST in?
IRST operates on its local timezone.
What timezone is Singapore in?
Singapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.
What are the business hours in Singapore?
Standard business hours in Singapore are 9:00 AM - 6:00 PM SGT.
Which countries use IRST (Iran Standard Time)?
IRST is used in Iran.
Does IRST observe daylight saving time?
Yes, IRST switches to IRDT during summer months.
What are some interesting 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).
Which cities are in the SGT timezone?
Major cities in the SGT timezone include Singapore.
What is the UTC offset for SGT?
Singapore Standard Time (SGT) is at UTC+08:00.
What should I know about the SGT timezone?
Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00). Singapore does not observe daylight saving time.
When is it midnight in IRST, what time is it in Singapore?
When it is 12:00 AM (midnight) in IRST (IRST), it is +4h 30m later in Singapore (SGT).
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