It's very difficult, if not impossible, to determine the life of a sharpening by the number of hours of use, especially if you skate on different types of ice. The best way to tell if it's time to have your skates sharpened is by how they feel while you're skating. If you feel that your blades no longer bite the ice when you push forward, it's a sure sign that sharpening is called for.

It's always a good idea to have your skates sharpened on a regular basis, for your own safety and to extend the life of your blades. Proper blade care (wiping, drying, storing in a dry place) prevents rust and prolongs sharpness. And of course, wearing blade guards when out on the ice prolongs sharpening, as the blades are protected from abrasive materials such as wood, cement or ceramics.