Advanced Sunrise and Delayed Sunset-

ADVANCED SUNRISE AND DELAYED SUNSET The sun is visible to us about 2 minutes before the actual sunrise and about 2 minutes after the actual sunset because of atmospheric refraction. Actual sunrise means actual crossing of the horizon by the sun. In the figure 2.14 this situation is shown. It shows the actual and apparent positions of the sun with respect to the horizon. So the difference between actual sunset and apparent sunset is about 2 minutes. The apparent flattening of the sun's disc at sunrise and sunset is also due to the same phenomenon.