I have a flight from SJD to LAS with an overnight stop in DFW (by design) departing on the 15th and arriving on the 16th. Can I fly standby on 2nd segment from DFW to LAS on the 16th? Can I fly standby on any available flight on the 16th, or only those flights that depart within 24 hours of the arrival flight into DFW? You cannot book a flight with more than a 24 hour layover, but I am not sure if that same rule applies to same day standby.