This is a real DIY project, hack your old alarm clock, connect it to the Arduino board, write some Phyton script to access your Google calendar and download the data to the Arduino. This will result in a versatile alarm clock, which the author named Larmie.
The alarm clock uses the LM8560 , if your clock has other IC then you must adapt the project, otherwise with the step by step explication it is easy to replicate the Larmie. You can use any calendar software, but I think the Google calendar is the best choice, because you can set your alarm remotely.
The downside of this device is that you need to run your PC all the time, it would be nice to use the Ethernet shield with TCP/IP stack and access directly from Arduino the calendar. Also it would be great if beside the plain 7 segment display some LCD display would show the reason why you should wake up at 6am.