An adjustable window awning/light shelf includes a canopy attached to supports on both sides of the window. The supports are engaged with vertical drive screws providing for the possibility of moving the canopy up and down. Each drive screw is connected with a common drive shaft. During the cooling season, the canopy is disposed at the top of the window, shading the window from the sun. During the heating season, the canopy is brought down to the bottom of the window by rotating the drive shaft, which in turn rotates the drive screws and moves the supports with the canopy down. Canopy's angle relative to the window increases. When in the bottom position, the awning performs as a light shelf, reflecting sunlight into the window and increasing the amount of sunlight and solar heat entering the building through the window.