You stand before a decent campsite and wonder: Should I opt for this one or keep hiking in hopes of finding that perfect site? But you left your watch home and don't know how many hours of daylight are left. To estimate hours before sundown, the only equipment you need is your hands. Extend your arms before you and bend your wrists so your palms face you. Stack one hand on top of the other from the horizon to the sun. Each finger represents approximately 15 minutes. Each person's finger size varies, so for accurate results every time, do this at home with a watch to see if you have 10-, 15-, or 20-minute fingers.
Telling time without a watch is just a few digits away.