TL;DR I used a ATmega328P (naked, internal oscillator), a battery-backed RTC (DS1307), and 5 gorgeous DL3416/2416 modules (big ones from 1990, small ones from 1984) to show the time in 5 minute increments. All hand wired with 30AWG solid wire, in a laser-cut acrylic case (with red acrylic filter for better contrast on the front). It looks really awesome.
This was my first "real" start-to-finish project, took a while because procrastination, but I had some good encouragement and some help from a good friend.
I don't know if anyone will ever read the project logs, but at least they're quite detailed if anyone wants to use their own displays for something, and hopefully enlightening on some details.
Also it took more than 5 minutes to make.