Determine remaining daylight on your hand. Use this simple trick to measure the remaining daylight without a watch. Count the finger widths between the sun and the horizon. Each finger is equivalent to 15 minutes, with each hand totaling an hour.
You may refer to a truss as the rafter, but it's basically the skeleton of the roof, carrying the weight of the frame and supporting the walls of the building. Trusses are very important to preventing the walls from bending or flexing, more so.