CAT to IRST
+1h 30mCAT
CATSOURCEIRST
IRSTGreen rows indicate typical business hours (9 AM - 5 PM)
CAT and IRST on the World Map
The map below highlights the CAT (Central Africa Time) and IRST (Iran Standard Time) timezone regions across the globe.
CAT – Central Africa Time
UTC+02:00Central Africa Time (CAT, UTC+02:00) covers Zimbabwe, Zambia, Mozambique, Malawi and neighbouring countries.
- •Central Africa Time is fixed at UTC+02:00 with no daylight saving.
- •CAT matches South Africa Standard Time (SAST) all year.
- •It is the same offset as Central European Time in winter.
- •Harare is level with Johannesburg and one hour ahead of Lagos.
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.
Time Conversion Guide: CAT to IRST
CAT runs on Central Africa Time (CAT) at UTC+02:00. IRST runs on Iran Standard Time (IRST) at UTC+03:30. That puts CAT 1 hour 30 minutes ahead of IRST — a difference of +1h 30m at the current offsets.
In practice, when it is 9:00 AM in CAT it is 10:30 AM in IRST. Midnight in CAT is 1:30 AM in IRST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
CAT to IRST time conversion table
| CAT (CAT) | IRST (IRST) | Day |
|---|---|---|
| 12:00 AM | 1:30 AM | same day |
| 6:00 AM | 7:30 AM | same day |
| 7:00 AM | 8:30 AM | same day |
| 8:00 AM | 9:30 AM | same day |
| 9:00 AM | 10:30 AM | same day |
| 12:00 PM | 1:30 PM | same day |
| 3:00 PM | 4:30 PM | same day |
| 5:00 PM | 6:30 PM | same day |
| 6:00 PM | 7:30 PM | same day |
| 9:00 PM | 10:30 PM | same day |
Why people convert CAT to IRST time
- Scheduling a call from CAT to IRST: a 10:00 AM start in CAT lands at 11:30 AM in IRST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both CAT and IRST are inside the 9-to-5 working day between 9:00 AM and 3:30 PM CAT time (10:30 AM–5:00 PM IRST). That is roughly 6 hours 30 minutes of usable overlap.
- Watching a live event or market open: CAT viewers need 10:30 AM in IRST to catch a 9:00 AM start there, and 10:30 PM if the event is anchored to CAT.
- Always state the zone abbreviation, not just the hour. "3:00 PM CAT" is unambiguous; "3 PM" across a +1h 30m gap is not.
- Block 9:00 AM–3:30 PM CAT as the recurring meeting window if you work primarily from CAT and need IRST colleagues present.
About CAT (Central Africa Time)
Central Africa Time (CAT) is fixed at UTC+02:00 all year across a broad belt of southern and central Africa, including Zimbabwe, Zambia, Mozambique, Malawi, Rwanda, Burundi and the eastern Democratic Republic of the Congo. None of these countries observes daylight saving time, so CAT never shifts. It is the same offset as South Africa Standard Time (SAST) and the winter version of Central European Time, which makes CAT a convenient bridge between African, European and Middle Eastern schedules — Harare is level with Johannesburg all year and one hour ahead of Lagos.
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 CAT and IRST
Both CAT and IRST sit inside the 9 AM – 5 PM working day between 9:00 AM–3:30 PM CAT, which is 10:30 AM–5:00 PM IRST. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
CAT and IRST share 6 hours of working-hours overlap (9:00 AM–3:30 PM CAT), so scheduling a live meeting is straightforward.
CAT is 1 hour 30 minutes ahead of IRST (CAT UTC+02:00 → IRST UTC+03:30). The shared working window is 9:00 AM–3:30 PM CAT. 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 CAT and IRST?
CAT (CAT, UTC+02:00) is 1 hour 30 minutes ahead of IRST (IRST, UTC+03:30). The gap is currently +1h 30m.
How do I convert CAT time to IRST time?
Add +1h 30m to CAT local time. For example, 9:00 AM in CAT is 10:30 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 +1h 30m offset from CAT.
What is the best time to call IRST from CAT?
Call between 9:00 AM and 3:30 PM CAT — that maps to 10:30 AM–5:00 PM IRST and keeps both parties inside the working day.
Which is ahead, CAT or IRST?
CAT is 1 hour 30 minutes ahead of IRST. When it is 12:00 PM in CAT it is 1:30 PM in IRST.
Does daylight saving time affect the CAT–IRST difference?
Neither zone observes daylight saving time, so the +1h 30m offset between CAT and IRST is fixed all year.
Which other cities share CAT's time zone?
CAT also covers Harare, Lusaka, Maputo, Lilongwe, Kigali.
Which countries use CAT, CAT's zone?
CAT is used in Zimbabwe, Zambia, Mozambique, Malawi, Rwanda, Burundi, DR Congo (east).
Is there a day difference between CAT and IRST?
Not normally. The +1h 30m gap only pushes the date over for late-evening times.
What is the time difference between CAT and IRST?
IRST is +1h 30m from CAT.
What timezone is CAT in?
CAT operates on its local timezone.
What timezone is IRST in?
IRST operates on its local timezone.
Which countries use CAT (Central Africa Time)?
CAT is used in Zimbabwe, Zambia, Mozambique, Malawi, Rwanda, Burundi, and 1 more countries.
Does CAT observe daylight saving time?
No, CAT does not observe daylight saving time and remains at UTC+02:00 year-round.
What are some interesting facts about CAT?
Central Africa Time is fixed at UTC+02:00 with no daylight saving. CAT matches South Africa Standard Time (SAST) all year.
Which cities are in the IRST timezone?
Major cities in the IRST timezone include Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
What is the UTC offset for IRST?
Iran Standard Time (IRST) is at UTC+03:30. During daylight saving time, it shifts to IRDT.
What should I know about the IRST timezone?
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).
When is it midnight in CAT, what time is it in IRST?
When it is 12:00 AM (midnight) in CAT (CAT), it is +1h 30m later in IRST (IRST).
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