Calendar 6.0 all-day events not visible

Please, please can someone at Apple pick up on this one? It's been going on for quite a while, and there has been plenty of discussion about the various permutations of the issue. I've set up two separate Calendars on my iPhone to roster night and day shifts. The ALL-DAY events show up fine on the iPhone and sync to iCloud. The data also syncs to Calendar on my Mac -- the search finds the entries -- but the events don't show up in any of the views: Day, Week, Month, or Year. Changing Preferences doesn't seem to make any difference.