Outlook Web Access

When using Outlook Web Access, why don’t all day events such as vacations show on the calendar? A single event that is not all day will show but something such as vacation time will not show when using Outlook Web Access even though it shows in Outlook 2000. It doesn’t matter whether there is a start and end time or date for each occurance. The only thing that works is entering the data through Web Access which defeats the prupose of using web access to see a schedule already posted.