The answer is complicated. For some reason the question always seems to mean that the 'act' of actually 'cutting and sewing' is all there is.
When a design has been rolling around in someone's head for weeks, does that time count? Is this not part of the quilting process?
When attempting to answer this question how can one disengage the process from the product? Where does production start and the processing stop?
Those invisible firing of little designing brain waves build into the very visible quilting Tsunami that overtakes the world and leaves my family with un-ironed clothes and substandard food.
Consummating a design can be breath-taking. Food, sleep, time all become irrelevant. The perfect storm never happens from a tiny breeze, or an insipid cloud. It requires accumulated power and energy. It can be beautiful and devastating at the same time.
Occasionally the storm leaves nothing behind but lessons learned. Sometimes a treasure is cast up and celebrated. No matter the outcome there is a 'rush' of being in the zone, and putting all that thought into something tangible.
Do daydreams, testing of products and techniques, researching, staring intently at some natural beauty count towards my final quilting time tally?
I may not be able to tell anyone how many hours I spend on my craft, but I can forecast: "cloudy with a chance of quilting".