Here is the schedule of panels with me on them at Comic-Con International in 2003. You'll note that most of these panels are in 90-minute time slots which means the panel itself generally ran 75 minutes to allow for the changeover to the next panel. Since sometimes, the next panel in that room was hosted by me, I could go a bit longer…and in 2003, for example, the Sal Buscema panel didn't really end. It just kind of morphed into the Stan Goldberg panel.
Over the next few years, there were so many people who wanted to do panels — mostly to promote business enterprises but some that didn't — that 90-minute panels became scarcer. I began doing more panels in one-hour slots, which usually meant wrapping things up after 45 or 50 minutes as people began wandering in to claim seats for the next panel in the room.
The exception to this would be any panel in a room with a number that started with a "6." Those panels were and still are spaced on the schedule to allow fifteen minutes for changeover…so the announced end time was or is actually the time we would usually end. Once in a while, I end them a bit earlier if it feels right.
In 2003, they finally gave me big rooms for Quick Draw! and the Cartoon Voices Panel and I did something dumb with the latter: I invited lots of people to be on it…more than twice as many as I should have had up there. It was fun in a way but some panelists didn't get to say very much and there was much scrambling for microphones. I had earlier made that same mistake with the Golden Age Panel so I should have known better…