By contract the company has you for 17 workdays. If the first of those days or the last of those days has you working (operating as opposed to positioning) then you'll need to Gateway on a day off to get there in in time or get home after the trip is done. Mostly, it depends on where you live as to how often that happens. I live in the hinterlands of northwest Montana so I do it often. If you live near a major airport it will happen less often. The key is to see when your trip begins Z time and then work backwards to figure that out.