Originally Posted by Steve M

Specifically, for international itineraries, "a stopover occurs when there's a break in travel of at least 24 hours." So, you could arrive at a particular airport at 7pm, and as long as the continuing flight is scheduled to depart by no later than 6:59pm the next day, it's a connection and not a stopover. I frequently use this when departing internationally to take the flight from my originating city to the hub airport where my int'l flight departs the following day. This makes it much less likely that I'll miss the long-haul flight due to a problem on my initial flight.