Helping My Husband Not Miss Appointments

My husband has ADD and one of the things he struggles with is keeping up with appointments that are on his Outlook calendar.  I would love to help him with this, but I do not have Outlook.  I use Google Calendar instead.  Does anyone know if there is a way for his Outlook calendar to automatically notify me by email each time a new appointment is scheduled?  I know one way would be for him to invite me to any appointment he has, but we are looking for a solution that will be automatic, not one that will create more work for him.  Thanks for any suggestions you may be able to offer me.