Edward Ringel as built Yet Another GPS Alarm Clock that does quite a lot more than tell time.

An alarm clock with everything!  Has a high accuracy temperature compensated clock (DS3231), automatic sync to GPS time, large touchscreen user interface, handling of time zones and daylight savings time.

Code and schematics for the project are available on the ElektorLabs project page, but it looks like you will have to create an Elektor account to access them.