Lesson Five: Time-Setting Buttons
One of the best things about 'physical computing' like you're doing is that code can interact with the real world. This program illustrates that by adding two buttons so that you (or anyone else) can change the time without digging into the code.
After this lesson, someone besides the developer (you) should be able to interact with your creation and make it work! Now your code is working in the real world like an alarm clock.