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Global ClockTime zone converter & meeting planner
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09
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18
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AUTO follows the operating system. Working hours drive the green banding on every grid. All four persist on this device only.

Time in Istanbul vs Guantánamo

Istanbul keeps UTC+3 (UTC+3) and Guantánamo keeps UTC−4 (UTC−4) today. Guantánamo is 7 hours behind Istanbul; the rows below read both clocks live.

The working day, side by side

Hours shaded in both rows are inside working hours in both cities: 09:00–11:00 in Guantánamo (16:00–18:00 your time).

Istanbul and Guantánamo hour by hour, with the working-hour overlap shaded
City00:00 in Istanbul01:00 in Istanbul02:00 in Istanbul03:00 in Istanbul04:00 in Istanbul05:00 in Istanbul06:00 in Istanbul07:00 in Istanbul08:00 in Istanbul09:00 in Istanbul10:00 in Istanbul11:00 in Istanbul12:00 in Istanbul13:00 in Istanbul14:00 in Istanbul15:00 in Istanbul16:00 in Istanbul17:00 in Istanbul18:00 in Istanbul19:00 in Istanbul20:00 in Istanbul21:00 in Istanbul22:00 in Istanbul23:00 in Istanbul
Istanbul——000102030405060708091011121314151617181920212223
Guantánamo——000102030405060708091011121314151617181920212223
  • Working hours
  • Shoulder
  • Night
  • Overlap

Do more with Istanbul and Guantánamo

Open in the PlannerAdd more cities, find a meeting time that works for everyone, then share it as a link.Open in Watch ViewKeep Istanbul, Guantánamo and other cities on screen as live clocks, under an animated sky and sun.

Best hours to call

16:00 in Istanbul
Inside working hours on both sides
09:00 in Guantánamo
17:00 in Istanbul
Inside working hours on both sides
10:00 in Guantánamo

Where daylight saving pulls them apart

Guantánamo next changes on Sunday 1 November 2026. Between those two dates the gap between the cities is an hour different from the one shown above — which is exactly when a recurring meeting drifts. Every date we track is on the daylight saving page.

Also useful

Common questions

How many hours ahead is Guantánamo of Istanbul?

Guantánamo is 7 hours behind Istanbul right now. The gap is not fixed: it moves whenever either side changes its clocks.

What is the best time to call between Istanbul and Guantánamo?

Any hour in 16:00–18:00 Istanbul time is inside working hours in both cities.

Do Istanbul and Guantánamo change clocks on the same date?

Only one of them does, so the gap between them changes twice a year even though neither city moved relative to the sun.