Offset
The time difference between Cuba Standard Time and Iran Standard Time is 7.5 hours.
Cuba Standard Time (CDT) is behind Iran Standard Time (IRST).
CDT: UTC-4
IRST: UTC+3:30
Cuba Standard Time is currently observing daylight saving time; Iran Standard Time is not.
When to schedule
Business-hours overlap: 9 AM–10 AM in Cuba Standard Time (4 PM–5 PM in Iran Standard Time).
Both teams are in working hours during this window on weekdays.
Suggested time: 9:00 AM Cuba Standard Time (4:30 PM Iran Standard Time).
This window may shift by an hour during daylight saving time.
Public holidays in 2026
National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.
Cuba
- Triumph of the RevolutionThu, Jan 1
- Victory of Fidel CastroFri, Jan 2
- Good FridayFri, Apr 3
- Labour DayFri, May 1
- Day before the Commemoration of the Assault of the Moncada garrisonSat, Jul 25
- Commemoration of the Assault of the Moncada garrisonSun, Jul 26
- Day after the Commemoration of the Assault of the Moncada garrisonMon, Jul 27
- Independence DaySat, Oct 10
- Christmas DayFri, Dec 25
About these zones
Cuba Standard Time is also known as CST, or CDT. To call Cuba, dial +53.
Iran Standard Time is also known as IRST. To call Iran, dial +98.
Iran Standard Time is approximately 7,350 miles northeast of Cuba Standard Time.
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| CST-CUBA | IRST | Day |
|---|---|---|
| 12:00 am | 7:30 am | Same day |
| 1:00 am | 8:30 am | Same day |
| 2:00 am | 9:30 am | Same day |
| 3:00 am | 10:30 am | Same day |
| 4:00 am | 11:30 am | Same day |
| 5:00 am | 12:30 pm | Same day |
| 6:00 am | 1:30 pm | Same day |
| 7:00 am | 2:30 pm | Same day |
| 8:00 am | 3:30 pm | Same day |
| 9:00 am | 4:30 pm | Same day |
| 10:00 am | 5:30 pm | Same day |
| 11:00 am | 6:30 pm | Same day |
| 12:00 pm | 7:30 pm | Same day |
| 1:00 pm | 8:30 pm | Same day |
| 2:00 pm | 9:30 pm | Same day |
| 3:00 pm | 10:30 pm | Same day |
| 4:00 pm | 11:30 pm | Same day |
| 5:00 pm | 12:30 am | +1 day |
| 6:00 pm | 1:30 am | +1 day |
| 7:00 pm | 2:30 am | +1 day |
| 8:00 pm | 3:30 am | +1 day |
| 9:00 pm | 4:30 am | +1 day |
| 10:00 pm | 5:30 am | +1 day |
| 11:00 pm | 6:30 am | +1 day |
Daylight saving time
Cuba Standard Time observes daylight saving time; Iran Standard Time does not. The offset between the two zones changes when Cuba Standard Time transitions: on Sunday, November 1, 2026, clocks fall back from CDT to CST.
See the daylight saving time page for transition dates across every time zone.
Daylight today
- Sunrise
- 6:44 AM
- Sunset
- 8:14 PM
- Day length
- 13h 30m
- Sunrise
- 4:50 AM
- Sunset
- 7:18 PM
- Day length
- 14h 28m
Daylight overlap: 5h 4m — 6:44 AM–11:48 AM in Cuba Standard Time (2:14 PM–7:18 PM in Iran Standard Time). Both locations are in daylight during this window.
Cities in these zones
Cities in Cuba Standard Time
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Cuba Standard Time
- HAV
Airports in Iran Standard Time
- IKA
- THR
- MHD
- IFN
- PYK
- TBZ
Related conversions
Common conversions
- What is 9:00 am CST-CUBA in IRST?
- 9:00 am CST-CUBA is 4:30 pm IRST.
- What is 12:00 pm CST-CUBA in IRST?
- 12:00 pm CST-CUBA is 7:30 pm IRST.
- What is 12:30 pm CST-CUBA in IRST?
- 12:30 pm CST-CUBA is 8:00 pm IRST.
- What is 2:00 pm CST-CUBA in IRST?
- 2:00 pm CST-CUBA is 9:30 pm IRST.
- What is 5:00 pm CST-CUBA in IRST?
- 5:00 pm CST-CUBA is 12:30 am IRST, the next day.
- What is 11:30 pm CST-CUBA in IRST?
- 11:30 pm CST-CUBA is 7:00 am IRST, the next day.