When I create an all day event, for instance, from 5/8/2012 to 5/10/2012, it will only show up on the calendar views (WebMonthView, WebWeekView, and WebDayView) as a full day event on 5/8 and 5/9, saying that it ends at midnight on 5/10. It should include 5/10 as having the all day event too because if I create a single day all day event that start on 5/8 and ends on 5/8, it will show as all day even though it says it ends at midnight on 5/8.
Here is a screen shot of the multi-day all day event from 5/8 to 5/10. The tooltip shows the start and end date and time:
I'm using Version 11.1.20111.1006 of Infragistics
I tested the scenario you have described with NetAdvantage 11.1.20111.1006. The behavior you are experiencing occurred only when All Day Event is unchecked and the end time is set to 12 AM. When this checkbox is checked, the dropdowns for start and end hour disappear and these values are automatically set to 12AM for start date and 11.59PM for end date. The multi day event now should be displayed for the last day of the event too.
If you have any questions, please do not hesitate to ask.
Please let me know if you have any other questions.