In reply to twm.bwen:
Did this years ago in full winter, descent of Am Bodach was fully banked out with fresh snow, cornices and beneath this, ice. We set of from the car at first light, completed the traverse and remember a bit of a hairy descent on the Clachaig end, getting back to the road just as darkness was falling, that having to walk several miles back up the road in the dark to retrieve the car. We used no ropes (nor did we carry one), single axe and crampons only.
Not sure what time it took as can't remember whether it was Dec, Jan or Feb and daylight times vary? Guessing around 8 hours though from car until back to car - basically it's a full day outing. We were young, fit and overtook an awful lot of people on the ridge. Suspect the people saying 3-4 hours for the round trip might be related to the late, great Ueli Steck!
So I'd say, start off at or just before first light and expect to be descending into the dark. It's a great day out, and hopefully someone will give you a lift back up the road, as we know from first hand experience, it's a long old walk in the dark.
Post edited at 15:35