I created this form in Google Spreadsheets so that our coaches would have an easy way to let us know that the time of lesson has changed. It is supposed to be right next to the schedule. It also has second list, which contains names and email addresses. A coach fills in names, day and time and hits send button. A notification pops up to let him know that the message has been sent successfully.
Copy this to your Google Drive: https://docs.google.com/spreadsheets/d/1ASVJ816mrkI0_dv_-7HZtNeXfUJf6iRuZAdnYKeh6cA/edit?usp=sharing