There's a bug with the assumption that multi-day, all-day events' due date is 00:00 of the next day (e.g. an event spans from Monday to Wednesday is assumed to have the due date to be on Thursday at 00:00).
That is no longer the case in macOS 13. The due date for multi-day events are now set to be 23:59:59 on the due date. This causes icalBuddy to display one day shorter than the actual event. The same Monday-Wednesday calendar event is now rendered as Monday-Tuesday.
There's a bug with the assumption that multi-day, all-day events' due date is 00:00 of the next day (e.g. an event spans from Monday to Wednesday is assumed to have the due date to be on Thursday at 00:00).
That is no longer the case in macOS 13. The due date for multi-day events are now set to be 23:59:59 on the due date. This causes icalBuddy to display one day shorter than the actual event. The same Monday-Wednesday calendar event is now rendered as Monday-Tuesday.