Few days after the awarded schedules were final seniority base trading opened for a day or two. You could trade or drop anything you wanted as long as the days were in the green. If the days were red you could still swap trips as long as the trip or trips (ex. 3 day and a 1 day for a 4 day) covered the same days of the original trip. When the seniority trade window closed, everything after that was first come first serve at that point. If something popped up in open time the fasted guy got the trip. I routinely ended up dropping most of my trips by waiting for the days to turn green throughout the month. The trades and drops were instatenious, no waiting like at United.