As you probably have noticed, people in Nicaragua tend to operate on a slightly different time schedule. The word “late” seems to be reserved for those who never arrive. Nowhere is this more evident than on the coast. Blame the heat and humidity. Blame the lack of transport. However, much of the reason is cultural, which means there is no blame to lay.
The concept of stating an hour to be/meet/do somewhere/someone/something does not mean at the stated hour (like in the western world), but during the stated hour. For example, if your local friend says she will meet you at 8pm, she means within the hour of 8pm, or somewhere between 8pm – 9pm. She may arrive at 8:45pm and be right on time!
If you are on a tight schedule, 1. Shame on you. Find a hammock, put on the reggae and relax. 2. Tell her to meet at 8pm en punto. Of course, that usually only shortens the wait from a possible hour to about 15 minutes, but this is how most locals schedule their time.