I understand that most airlines have a 24 hour stopover rule which states that on an international flight if the connecting time at the intermediate point is less than 24 hours, it will count as a layover instead of a stopover (which typically costs extra). For example, the United Contract of Carriage states:
Stopover means a deliberate interruption of travel by the Passenger, agreed to in advance by the carrier, at a point between the place of departure and the place of destination. For International flights a Stopover will also be deemed to occur at an intermediate point from which the Passenger is not scheduled to depart on the date of arrival, but if there is no connecting departure scheduled on the date of arrival, departure on the next day within 24 hours of arrival shall not constitute a Stopover. If a portion of the routing is traveled by surface transportation, one Stopover shall be deemed to have been taken for such portion. For Domestic flights, a Stopover will also occur when a Passenger arrives at a point and fails to depart from such point on:
1) The first flight on which space is available; or
2) The flight that will provide for the Passenger’s earliest arrival at intermediate or junction transfer point(s) or destination point, via the carrier and class of service as shown on the Passenger’s Ticket; provided, however, that in no event will a Stopover occur when the Passenger departs from the intermediate/junction point on a flight shown in the carrier’s official general schedule as departing within four hours after arrival at such point.
My question is: what is the definition of an International flight? If I fly, from Los Angeles to London stopping in New York City on the way, can I spend up to 24 hours in New York without counting it as a stopover? The first segment is domestic (LAX-JFK), but the second segment (JFK-LHR) is international. How does this work? Does it depend on the airline?
Finally, what is the best way to book a ticket like this? I cannot get long layovers to appear on any site online.