There's a link there to a his Shanghai Time nixie clock [1],"a two-tube nixie clock". I wonder how you read a two-tube nixie clock. From the pictures it looks like it just displays the minutes, but that wouldn't be enough info for me. I'd be like "OK, I see it's 10 past, but 10 past what? Judging from the position of the sun, it may be 10 past 2 or 10 past 3. Not sure though."

[1] http://www.daliborfarny.com/shanghai-time-nixie-clock/