Tuck,
Not sure about that one, but here's something else to be aware of. The last time I swapped a carryover trip for a carryover trip in open time, I found that it did not affect my swap bank for the month in which the trip started. It affected only the month in which the trip ended. If you're trying to boost your present month's paycheck, you won't see that happen. If you have no problems with delayed gratification, you're all set.