The answer is “depends”. The length of time you can stay in Cuba depends on your passport and the purpose of your visit.
In general, a Cuban visa is valid for 30 days, but there are exceptions. For example, a Cuban visa for tourism is valid for 30 days, but a Cuban visa for business is valid for 60 days.
The length of time you can stay in Cuba also depends on the purpose of your visit. For example, you can stay for 30 days if you are visiting Cuba for tourism purposes. However, if you are visiting Cuba for business purposes, you can stay for 60 days.