User Agent: Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:10.0.2) Gecko/20100101 Firefox/10.0.2 Build ID: 20120216101208 Steps to reproduce: I've added a google calendar with the google plugin to lightning in thunderbird. Actual results: Once lightning is properly installed into thunderbird, it uses it's own column to the right of the mail view. There's a small overview calendar showing a month view with just a number for each day of the month. These numbers are printed in a bold font if there's an event in calendar for that particular day. Unfortunately, this sort of marking (bold font) is not used if the event is an all day event. Thus, you don't see that there is an all day event marked on that day and erroneously assume that this day is free of events (and available). Expected results: Mark numbers fat (bold font) if there's an all day event for that day. (or if you don't like that, add a configuration option to choose.)
The mini-month doesn't show event indication, it shows free-busy indication. Therefore is depends on event setting, i.e. if your all-day event is marked as 'show time as free' or 'show time as busy'.
Resolving as invalid per comment#1