> Isn't this kind of opacity usually implemented in the compositing > manager (e.g. xcompmgr/picom)?
Good idea, I could start entering the 21st century, eh? But after installing `picom` I see that the problem is worse: that gives me control over the transparency of the whole window, whereas I only want the background to be transparent. Hmm... I suspect this problem will need fixing on the side of `xdaliclock`. Stefan