JeanH is right. By bus it's about 4 1/4 hours from Playa to Chetumal, then figure another hour or so to cross the border and get to the Coro air strip (plus connections time). So, on average maybe 7 hours. During daylight savings time, you gain an hour coming into Belize, as Belize does not observe daylight savings time, while Mexico does. Lose an hour in the other direction.