It depends on how much you use them and what you use them for. In general, it is recommended to sharpen your knives regularly to maintain their sharpness. For the home chef, sharpening your knives every 3-6 months may be sufficient, depending on usage.
If you use your knives frequently and more intensively, you may want to sharpen them more frequently, perhaps every 1-3 months. It is also important to remember that it is better to sharpen your knives more often and maintain a sharp edge, than to wait until they become extremely dull and have to grind off a lot more material.
Please contact us for advice on the sharpening frequency that best suits your knives.