I tried to use ITN to see how many seats left for flights from NRT to MEM via LAX by NW. If I don't divide it to 2 legs (NRT-LAX and LAX-MEM), it'll show only flights via MSP and SEA. If I force it by putting NRT-LAX and LAX-MEM, it won't accept because the time that the flight from LAX leaves is before the departure time of the flight from NRT due to the time zone change. (LAX is about 16 or 17 hours after NRT but the flight from NRT to LAX is about 10 hours.) ITN should also check the time zone.