When Orage is first started, it may show wrong dates. This is caused by the delay in reading preferences. It is possible that first time when mark appointments is done in the main window, default timzone has not been initialized and wrong results may happen depending on your appointments and location.
Created attachment 727 sampel ics file
fixed in svn revision 22744. Will appear in 4.4 RC1. own (default) timezone was read only after marking calendar with appointments, so it was possible to mark wrong days.
Moving all bugs to new Orage product.