Years ago when I was an impetuous thing[&:]I took shots later than anyone should. I learned after a few marginal hits and long tracking jobs, it just isn't worth it. I no longer check to see when sunset or sunrise are. I now go by the rule of, if I can't see my pins clearly it's time to call it quits. I used to stay in a tree until I couldn't see the ground. Now I get down with enough light to see to walk a ways in the daylight. I get down leisurely and amble out. There are other days and lots of deer. If I'm hunting dark cover, like a cedar swamp, it's often light enough when I get out to see deer in fields, yet it was dark thirty in the swamp. Cloudy overcast days it's too dark for me long before legal shooting hours have passed. If I can't see my pins well through the peep it's time to get down.