When you see a small parallelogram-shaped window along with the faces of the crystal that is leaning back towards the right, it is a right Time Link Window. It must truly be an extra facet (there are 6 facets on all quartz crystals) to be a time link window.
These are for manifesting and setting intentions for the future and creating the realities that you wish to come into being. They are also useful for breaking the illusions of time.