Linux is the only OS to support diagonal PC monitor mode — dev champions the case for 22-degree-rotation computing::A Linux developer has eschewed boring traditional landscape and portrait monitor orientations and is championing diagonal modes, with 22 degrees claimed to be the sweet spot.
It also mentions that the 22 degrees is based on your monitor and that was what they settled on, and even goes on to provide a handy calculator to figure out your own best angle.