This is a crude solution, not exactly what you want, but works ok for me. It has the advantage of not being restricted by the warping height rules. I get my departing ship into orbit (or leave it on the pad), then switch to something I have on the ground (flag, ship, rover, whatever). Make a note of the now current ship's mission time and then start warping while you watch the planets spin. Switch back to your (starving, dessicated) departure crew and away you go!