Created attachment 103896 [details] screenshot of the list view and edit view for the same task. Repeating to do list items shows different "start date" and "due date" in task list, from edit mode. Potentially relevant output from the terminal used to start the program: log_incidenceeditor: free slot calculation: invalid range. range( 0 ) / mSlotResolutionSeconds( 900 ) = 0 log_calendarview: got bizare parameters: QDate("2016-12-01") QDate("2017-03-31") - aborting here I can find no rhyme nor reason for the relationship between the parent tasks' due and start dates in edit mode, versus the start and due dates in the list mode (see screeshot). However, subtasks seem to be consistent that the list's start date is the edit mode's due date. All the tasks that I have tried with are recurring with a period of one year.
Newer versions of KOrganizer have fixed some date bugs, particularly for recurring to-dos. I can't reproduce this error in version 5.14.3 (20.04.3). Does it still affect you?
Created attachment 131211 [details] Date error still present in 5.11.3
5.11.3 is what I got when installing from Fedora 31's repos an hour ago.
I'm optimistic that this bug is fixed in version 5.14.3 (20.04.3); see bug 345498. I'm not a Fedora user, but if I understand https://rpms.remirepo.net/rpmphp/zoom.php?rpm=korganizer correctly, that version will be in Fedora 33.
According to bug 345498, the fix was committed to frameworks, which was made available as version 5.72.0. If you have an older version, you could ask in a forum of your distribution if a backport or version update is available or planned. Please reopen, if updating reveals it is actually a different issue. *** This bug has been marked as a duplicate of bug 345498 ***