I apologise in advance if you have already come across this simple way to see how you are doing for time. Fishing in the late afternoon and into the evening you may want to have some idea of how much time is left before sunset. The method is to open your hand as wide as you can. Aim your little finger at the horizon. Count the spaces between the fingers going up until you reach the sun. Each space equates to about an hour. So in this picture you can make out where the sun is at the time of taking the photograph by the little flare around my second finger below the tip. This indicates that sunset will be in just under two hours. In summer this often helps me decide when to move to get ready for the light changing and the fly life to get very intense and the evening rise to get underway. Give it a try if you haven't already. It is remarkably accurate, but you must force your hand open as wide as you can.