For playing the music, it uses the BY8001 MP3 Player module and for the alarm clock it uses the DS3231 Real Time Clock module.

[Barzok] has a very minimal clock build. It takes a handful of LED arrays with an integrated driver, an Arduino Nano, a real-time clock module, and a voltage regulator.

Developers, makers and hobbyists looking for a real time clock module complete with an Arduino library, may be interested in the Kraztech Real Time Clock Module created by developer Christopher ...