Automatic Invoicing Software

As a private tutor, I enter my monthly schedule into my google calendar. I need a piece of software written to perform the following tasks: 1. I select the month and customer (or all customers), push "go" and the information will be pulled from my google calendar and entered into an excel spreadsheet. 2. I select the month and customer (or all customers), push "go" and the software should then generate pdf invoices based on the information held in the spreadsheet. 3. I select the month and customer (or all customers), select either a preconfigured email or write a custom one, push "go" and the software should email those pdf invoices to the appropriate customer using my gmail account.