i have an overnight in LAX when doing SFO-MIA-LAX-LHR next month and i arrive at 4pm one day and continue on at 9am the next morning.
i do not want my luggage but was advised that because it is overnight that AA would not check it onwards to LHR/BA flt. the overnight rule negated the 12hr rule when i asked waht if i took a flight landing at 10pm instead and the overnight rule trumped all else.