If its a 2.0 every 60,000 miles, if it's a 1.8 turbo every 120,000 and if it's a 1.9 diesel every 100,000. These mileages are whats recommended in the Gates timing belt guide, Gates makes timing and other belts. The official answer is either in your owners manual or call the dealer. There is no definite life for a timing belt they will last till they break. But all 3 of the above listed engines are "interference engines" and waiting for the belt to break will most probably result in internal engine damage. So the best advice is get it changed at the specified interval (either time or mileage) or if you've gone over change it soon, before it breaks.