Tehran to SGT
+4h 30mTehran
IRSTSOURCESGT
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 Tehran
WikipediaTehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).
Tehran vs SGT: Offsets, DST and Best Call Times
Tehran runs on Iran Standard Time (IRST) at UTC+03:30. SGT runs on Singapore Standard Time (SGT) at UTC+08:00. That puts Tehran 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 Tehran it is 1:30 PM in SGT. Midnight in Tehran is 4:30 AM in SGT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Tehran to SGT time conversion table
| Tehran (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 Tehran to SGT time
- Scheduling a call from Tehran to SGT: a 10:00 AM start in Tehran lands at 2:30 PM in SGT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Tehran 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.
- Coordinating a Tehran-based team with SGT 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 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 Tehran 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 Tehran and SGT
Both Tehran 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
Tehran and SGT overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.
Tehran 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:
Frequently Asked Questions
What is the time difference between Tehran and SGT?
Tehran (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 Tehran time to SGT time?
Add +4h 30m to Tehran local time. For example, 9:00 AM in Tehran 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 Tehran.
What is the best time to call SGT from Tehran?
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, Tehran or SGT?
Tehran is 4 hours 30 minutes ahead of SGT. When it is 12:00 PM in Tehran it is 4:30 PM in SGT.
Do Tehran and SGT use different time zones?
Tehran (Iran) uses IRST at UTC+03:30, while SGT uses SGT at UTC+08:00. The IANA identifiers are Asia/Tehran and Asia/Singapore.
Does daylight saving time affect the Tehran–SGT difference?
Neither zone observes daylight saving time, so the +4h 30m offset between Tehran and SGT is fixed all year.
Which other cities share Tehran's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, Tehran's zone?
IRST is used in Iran.
Is there a day difference between Tehran and SGT?
Not normally. The +4h 30m gap only pushes the date over for late-evening times.
What is the time difference between Tehran and SGT?
SGT is +4h 30m from Tehran.
What timezone is Tehran in?
Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
What timezone is SGT in?
SGT operates on its local timezone.
What are the business hours in Tehran?
Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.
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 Tehran, what time is it in SGT?
When it is 12:00 AM (midnight) in Tehran (IRST), it is +4h 30m later in SGT (SGT).
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