At least stay open til 6:00.  Here's a true story why you should.  I work til at least 5:00 everyday.  It was my anniversary last week.  My plan was to run out on my lunch and pick up flowers for my wife.  The local florists in town are only open til 5:00.  Well, I got extremely busy and time got away from me...I never made it out to lunch.  When I left work at 5:30, my only choice was the grocery store on my way home.  Not what I wanted to do, but at that point I was left with no choice.