The "second dawn" is when you're still running when the sun comes up for a second time. Dawn has always been a time of renewal, as in "weeping may endure for a night, but joy comes in the morning." For ultramarathons a race can last all day, all night, and through the following dawn. This "second dawn" is an incredible experience, giving a sense of hope and rebirth. Even if the dawn is cloudy and dull, it is a think of intense beauty. The second dawn is most common for runners in 100 mile races, though it can occur at other distances.