I will provide figures for oil and latex, but drying times will depend upon a number of factors including the temperature outside (warm temperature means the paint will dry faster in a well ventilated room), the humidity level (humid air has more water in it and won’t allow the liquid to evaporate out of the paint), ventilation (circulating air through a room will allow paint to dry faster.

Latex paints dries to touch in about one hour. This isn’t the same as it being cured. Latex paint can be painted with a second coat after about 6 hours. It takes about 30 days for the paint to fully cure; meaning that you can wash spots off your wall without damaging your paint finish. Paint cures by reacting with oxygen in the air to form a skin over deeper, still wet layers. Eventually, oxygen reaches the deeper layers as well, drying them; thus the 30 day cure time.

Oil paints take longer to dry, to recoat and to cure. The first coat will take 12 to 24 hours to dry enough to apply a second coat. Oil paint also cures by binding with oxygen. I have read if you thin your oil paint, you can paint 2 thin layers instead of 1 or 2 thick layers. The thinned paint dries in less time.