Is it time to stop and scrounge for shelter or is it better to keep trekking? Use this simple trick to measure the remaining daylight. Remember to allow yourself at least two hours to set up camp before the sun goes down.
Count the finger widths between the sun and the horizon. Each finger is equivalent to fifteen minutes, with each hand totaling an hour. When the sun dips low enough that only two hands fit. It's time to search for a suitable campsite and assemble a shelter: (A caveat: if you're near the poles, the sun will hover over the horizon for a longer period of time, giving you an innaccurate reading.