It's very likely that your kitchen counter is covered in candy. Assuming you don't finish it off right away, how long before the candy goes bad? 

Most candy bars are high in sugar and low in moisture, both of which help to prevent microbial growth. Pure chocolate can last for two years or more without presenting any risks, but it's likely to change in texture and become less appetizing after about 12 months.  Given enough time, some bars could even become so dry and hard they can hurt your teeth. 

You also need to think about what's inside of the candy bar.  Almonds or peanut butter may degrade more quickly than the chocolate coating. Nuts can begin to go rancid after about a year.

Also,  if you see white spots on old chocolate bars, that's not mold.  It's actually harmless.  It's called blooming and it's a splotch of fat or sugar that has come to the surface.

Nutritional experts say, chocolate can last up to two years if it's stored in a dry, odor-free spot.  Hard candy can last a year.  Unopened packages of candy corn can last nine months.