I wanted a minimal, fullscreen clock I could run without X. In the longer term, I am thinking about a locking console “screensaver”; (more about that later). I ended up writing a small library (240 lines and counting) to render a 7-segment display in monospaced text at any “resolution”.
The end result adapts to the console size, instantaneously if resized. It lacks any options, if I'm bored again I might come back to it. It should be quite efficient, though more trivial optimizations are possible.
Older screenshots from various prototypes (the test program is available alongside the clock; as usual, I recommend sticking to the instructions in INSTALL at the root of the repo):
