Thank you for the comment.
Our support engineers answer ANY letter within 48 hours. If your domain is in spam list then probably your email could get into spam folder. You can always re-send the email to firstname.lastname@example.org, contact us using form on our site or ask a question forum.
Calendar groups are used to show several calendars in a single view.
Just please contact us by email with your issue and we will be happy to solve it for you and to set up an example if it is needed.
Thousands of customers use Art Calendar and we are always ready to provide free support.