Wait until just before slicing to wash your fruit. This extends the shelf life in your refrigerator.
Fruit salad can be prepared up to 6 hours in advance. Store in the fridge and wait until just before serving to add the banana. If you want to add other fruits that turn brown, such as B. Apples, also wait until just before serving before adding them. Stir again before serving. I don’t recommend making fruit salad a day ahead or refrigerating fruit salad overnight if this can be avoided, otherwise the fruit will become a bit mushy.