• That depends on how well you take care of them and how often you skate. Typically you can perform a finger nail test, hold you skate in your hand and slide your nail carefully (please don't cut yourself) on one of its edges just as if you were trying to shave it, if the nail shaves then your skates are sharp, if it doesn't then you probably need to have them sharpened. 
  • Another thing to look for are nicks in the blade, if you have them it's a good idea to sharpen your skates