It may depend on how thick or thin you are applying it, but in general I have never needed to let it dry more than overnight before masking or painting over it. In some case I have even done it within a couple of hours when masking is something simple and the tape won't be sitting on their long
If no masking is involved, then I will even paint and weather over it as soon as it is dry to the touch. I actually find there is a "sweet spot" in the drying time where you can do chipping, or scratches/damage where it is not fully dry, but not tacky either. That is usually when I can do things like run the xacto blade over some edges to creat knicked up paint etc...
I find Vallejo takes a bit longer to dry than Tamiya, but I also tend to do thicker coats with Vallejo