Adding a calendar event of the same date twice produced an error. The problem was the xf_calendar table had the thread_id field as a primary where it should have been made an index.
In addition to showing the "Today's Calendar Events" block in the sidebar, it's now possible to also show a "Tomorrow's Calendar Events" block in the sidebar.
1) Added Today's Calendar Events as a sidebar block option.
2) Remove Today's Calendar Events which was displayed above the forum list.
3) Added User Group Permission "Calendar View" which determines which user group can view the calendar.
Improved Calendar Thread links so they show correct URL format in all situations.
If you have already made a donation for this very popular add-on, thank you. Otherwise please consider making a donation to show your appreciation for the Calendar add-on. My PayPal email address will be given upon request via Private Conversation.
Made a minor code change to prevent Server Error Log entries in a rare situation where guests cannot view any nodes and the the Calendar is called from the URL.
Updated andy_calendar.css template to use @pallet colors. This allows in most cases to work with any color style.