When preparing your presentation, create two endings to ensure you meet your time limit.
Create a false ending, which could be a summary and also create a real ending—this could be a rousing, inspirational story that drives the message home. If you’re running long, you can drop the second ending and still get your message across. Once, at a TED event in India, Nancy Duarte was given a 15-minute time slot and had rehearsed it to a T.
Two days before the talk, she caught a severe chest cold, and was heavily medicated when she walked on stage. Before she knew it, the time was up, and Nancy wasn’t done. Fortunately, she’d planned two natural places to end the talk—and wrapped things up with the first ending, citing a beautiful salutation to the land of India from Nehru’s famous speech. As far as the people in the audience knew, that was the real ending—and they responded warmly.