Kayaking on top of a dormant volcano

Every morning, to get to work, I drive past a lagoon. At exactly 8:00 a.m the surface of the lagoon is 180 degrees, flat and calm, producing a mirror-like effect.

I've driven past this lagoon at different times of the day: 8:15 a.m, 9:00 a.m, 12:00 p.m, and 5:45 p.m, but at no other time does the surface look as close to a mirror than at 8:00 a.m.