Caulk is available as an acrylic, silicone or polyurethane product. It can be used in wet areas---such as a shower---or in dry areas---such as a window frame.
These drying times are a general guideline, as actual cure times can vary from one product to the next.
Caulk in a Wet Area
When caulking an area such as a shower or bathtub, allow the caulk to cure for 24 to 48 hours before getting it wet. Make sure that the area that is getting caulked is completely dry first, to achieve a better seal.
Most brands of acrylic caulk are ready to paint after two hours and completely cured in two to three days. Polyurethane caulk takes much longer to dry.
It is paint-able after two to three days and cures in one week.
Fast Drying Caulks
There are some exterior caulks on the market that feature a faster drying time than standard caulk. One product states that it can get wet a mere three hours after applying.
These caulks are more convenient for wet climates that get frequent storms.