How do you know when a medjool date has gone bad?

A Medjool date has gone bad if it exhibits an off smell, unusual stickiness, or a change in color, such as becoming overly dark or developing white spots, which can indicate mold. Additionally, if the date feels excessively dry or hard, it may no longer be good to eat. Always check for any signs of fermentation or sourness, as these are signs of spoilage. If in doubt, it's best to discard the date.