[JoeDaDude]

LED segments may be nice, but why not go full out Nixie tube? There are several kits out there, but for the DIY ethic, you can add WWV sync - and even watch the synchronization process - with this fellow's project:

https://www.youtube.com/watch?v=smUwbzA9SEo

[thesuitonym]

Nixie tubes are cool but they're also significantly more expensive, take up more space, and are more prone to failure.