Yes, mango salsa can be made ahead of time. If you want to, you can make the mango salsa as instructed and keep in in the refrigerator until ready to serve. The additional time will make the juices and flavors absorb a little more than if served fresh. If you prefer, you can also dice and cut all of the ingredients ahead of time but keep them in separate containers. Add all ingredients to a bowl and mix right before serving. You can store the salsa in the fridge in an airtight container for up to 7 days.