I went the clock route for my last nixie project, but I tossed in some extras: temperature, humidity, and barometric pressure displays too. If those are IN-12 tubes as mine were, you can get matching tubes with a bunch of symbols (designed for multimeters) and with the right configuration, I could get F (not C or degrees), kPa, %, AM, and PM for the display too.
I actually way overbuilt the design because I wanted to mess around making some i2c slave modules, but it can be hooked up to the computer and used as a generalized display for whatever, and coding in temperature offset (for being inside a box) or daylight savings time is simple enough.
Not super electronicsey since a lot of it was micros, but it was a fun project and it's been a great little display over for the last year.