gps_clock has the following features and characteristics:

• 16 digit 7-segment LED display.
• Date/Time display EPOCH format (seconds elapsed since 1970-01-01).
• Date/Time display ISO-8601 format (YYYY.MM.DD.HH.MM.SS).
• Adjustable brightness (setting retained with power-cycle).
• Programmable UTC offset from -12hrs to +12hrs in half-hour increments to match any timezone (setting retained with power-cycle).
• RTC with battery back-up to retain time with power-cycle and/or absence of GPS signal.

The code, schematics (control board & display board) and PCB layouts (control board & display board) are all included here on gitlab.

Additional info and photos can be found here.

Proudly mentioned at hackaday.com (and linked again in a later article).