This is an example how Service Objects can help you to code better. Please take a look at Sceduler before Service Objects for comparison and notice the differences in code and tests.
Besides that code is more readable, the tests are likewise easier to do. This example tries to follow the basic rules of thumb of keep it simple. If you haven't already read "Practical Object-Oriented Design in Ruby" by Sandi Metz, I can highly recommend it. It would help you to become a better Ruby developer (in fact, a better developer in any OO language).
If you have a suggestion to improvement, find a bug or have a question, please feel free to contact me.