Good point, Kevin. The OLED was definitely a poor choice for this project, but as mentioned in the description, we had one laying around and wanted to try it out in a real-life application. Version 2, if there will be any version 2, will have a different display. VFD is one option but there's also another one: e-paper. Although such displays don't glow so we would need to illuminate them slightly so that the time is visible in the dark. We shall see...