3.0 Miles and getting dark

Well I drove the distance that I run and it is only 3.0 miles. Even worse since I know I walk the first 0.4 and the last 0.1. So I'm only running 2.5 miles, which doesn't help me prepare for a 5k run. Also what is really bothers me is the face that it is getting darker now. So I am losing my window to run before dark. Not a good run tonight.