Sunlight patch in my study at home

Exactly once each year I get sunlight in my office. Here it is, this tiny patch reflected off the windows of the house across the road, through a narrow slit past strange angles in hall and living room and onto my bookcase. In a couple of days the angles won't line up any more at any time of day, and that'll be it for sunlight in my office for another year. Sixteen minutes of sunlight each year and here they are. It's the tick of a slow clock. It's like Stonehenge here in the Mission.