The chart for November on that page lists Leonids duration as Nov 14-20, peak activity on the 18th... See why I get sooo confused???

Yes, I see your point. When you look at the graphical charts, though, you can see why they list it that way. Depending on the year, we could hit a given cloud on different dates. They say that forecasting the Leonid activity is still a pretty young science. This year, it was basically the one night, and that was it.