This is just a variation to the desktop clock theme. Put a 4 digit 7 segment LED display to the center of a PCB what show the time. Maybe put a second smaller display under it for the temperature. It is just a normal digital clock until now. Naturally add an MCU, some LED driver and maybe some buttons.Here come the twist. Pick 60 LEDs (these are rectangular blue ones in my head) and put them in a circle around the display. In every second increment the number of LEDs switched on and when reach the end, start it over.
The clock can be expanded with some precise timebase: DCF-77, SNTP, GPS, distributed time source (homebrew), or something precise (more precise than the regular 32768Hz XTAL) but not atomic clock based one like a TXCO. Maybe something from here:
The whole thing goes ta a "Sick of Beige" enclosure together with the timebase what has a same size PCB like the clock itself. The whole thing screwed together with necessary spacers like a "sandwich".