Well, not really deadly, but can give you a nasty bite because there are 200V or so floating around on exposed wires.
The special things about this clock: - Just a 328P running on the internal RC oscillator - HV voltage generation driven by the 328 - Super low component count - Battery backed Real Time Clock - Software button debounce
The code is on GitHub https://github.com/isparkes/ArdunixNix6 (sub folder "SpiderClock").
And a YouTube video: https://youtu.be/gGaBfw0rWDA
Here are some stills: