How many hours of darkness are there in one day?

It depends on where you are and what season it is. If you are at the equator then there is 12 hours of daylight and 12 hours of night. If you are above the arctic circle then during the winter there is 24 hours of darkness each day, this will occur on Dec. 21st. If you are further above the arctic circle the darkness can last for months. During the summer there will be 24 hours of daylight on June 21st, and again this can last for months if you are very far north. The same is true for the South pole as well.