Brazil is divided into three time zones. Most of Brazil has the same time as the capital city Brasilia that is UTC -3. Florianopolis is also in this time zone.
Southern Brazil including Florianpolis uses Daylight saving time (DST). It starts on the 3rd Sunday of October and ends on the 3rd Sunday of February.
Sometimes in can be quite confusing to figure out what time it is in Florianpolis. For example in June is Floripa one hour ahead of New York and in November (as New York falls one hour back and Brazil springs forward) Florianopolis is three hours ahead of New York.
The easiest way to check what time it is in Brasil is to check Legal Time in Brazil.