Dawn to Dusk

This exercise is proving to be troublesome.  I am exhausted getting up at 3:30 to get sunrise only to find the weather unsuitable. London is too cloudy!! I am becoming an expert on how much cloud and when it comes in, how fast, how long, what shape.  Think I will move on to the next exercise.  I'll have to come back to dawn to dusk when I can get better weather, which may mean outside of London.