I assume we are talking about the porch floor, correct?
Really depends on temperature and humidity outside but something like Benjamin Moore Porch, Floor and Patio paint, oil-based, will usually dry within 24 hours and usually to the touch in 12 or so. Always read the can label so you are not surprised. Never apply outside if temperatures will fall and stay below the threshold.
I have nothing against oil based floor finishes but you might think about shifting to a waterbased product. The Ben Moore waterbased is epoxy reinforced (the oil based is urethatne reinforced) and is pretty amazing stuff. You can put it over oil based that is properly prepped. It is not quite as glossy as oil though.