Silicone caulk is used for a varied amount of things. It can be used as a seal around an edge, but it is mainly used to fill in cracks. The length of time silicone caulk takes to dry has no answer as silicone caulk does not dry at all. This caulk has a curing agent in it. This curing agent makes the caulk settle. The amount of time it takes to settle can be different. It depends on where the caulk is being used and the temperature.