Seven days is a long time, and will be a sure fire fail safe. Most of the time the silicone package will have stated full cure times. Most of the time, yes, it is only 24-48 hours depending on how much you 'pile-on' the silicone. More silicone, more dry time....the outside will feel cured in a couple hours, but the inside that is not exposed to air is what takes the longest.