After you bought some parts of old grandfather clock, you can begin with working on all the mechanics. See this log about the mechanics and fine tuning.

The circuit is not too complex but it would need some further development. See this log about the current schematic or check out the circuit on the DigiKey webpage. (Be aware of the needed power source.)

Then it is time to prepare your headless Raspberry pi. It is easier then you think. See this log how to do this.

The python code is not very complex and you can use different approaches. See this log about the code, or check out the github page of the project.

Enjoy you project. Try it with IFTT and/or make some improvement. Please, do not forget to share your progress.