Istanbul and Havana Time Zone Comparison
Istanbul and Havana are two major cities that sit in noticeably different time zones. Istanbul and Havana sit on different continents, in noticeably different time zones, and at least one of them observes daylight saving time.
Because Istanbul and/or Havana observe daylight saving time for part of the year, the gap between them isn't fixed — it ranges between 7 and 8 hours depending on the season.
With a gap this large, business hours barely overlap between Istanbul and Havana — an early morning or a late evening on one side is usually needed to connect with the other.