Here’s a very simple but helpful plugin for Moodle by Isuru Madushanka Weerarathna. Event Reminders is exactly what it sounds like, an extension which will utilize Moodle’s Message Center to send additional calendar event reminders to users.
The plugin provides configuration options for users to choose how the messages are received. Emails received are formatted with relevant information including a link to the course/resource/activity tied to the event.
Check it out and download it for Moodle 2.8 at https://moodle.org/plugins/view/local_reminders