My latest digital clock is based on this video and the code found there.
It works very well but I wanted something that also gave me auditory announcements of the time. The classic way of doing this is with Westminster Chimes. Such chimes are found on most grandfather clocks as well as mantle clocks.
While the Arduino that I am using for this project is capable of producing rudimentary sounds that could resemble Westminster Chimes I opted to use an MP3 player that sounded out recordings of the chimes. This gives much better audio quality and flexibility to use whatever sound you choose to play. It also allows me to change the version of the chimes that is played by simply swapping micro SD cards.
One of my clocks is shown here. It continuously displays the time and sounds the chimes at 15 minutes, 30 minutes and 45 minutes after the hour. On the hour where it also chimes the number of the hour.
Source: Adafruit – Arduino