In KOrganizer, I see the US holidays displayed. Even if I remove the US from the list of holidays in the configuration dialog, and add the Canada holdays, I still only see the US holidays. I've seen some old forum posts suggesting that for each region on the list, you should be able to specify whether to display or observe (my terms, I don't remember the originals) but I only see a checkbox, with no distinction between just displaying and actually treating as a holiday. Am I missing some other configuration setting?
Separately, the inclusion of holidays in the panel calendar widget seems to be controlled completely separately, by right clicking and then configuring the digital clock.
Should these be more integrated?

Thanks for any comments or suggestions.
EDIT: (more info) It seems there is a time lag involved. In KOrganizer, I do now see both US and Canada holidays (but some holidays, such as Mother's Day 21 May) do not list a country. However, the holidays do not match those shown in the panel calendar widget. For example, KOrganizer shows Victoria Day (CA) on 5/20 but the widget does not. The widget shows Ascension 5/30 (no stated region) but KOrganizer does not. Do these two pull their calendar/holiday info from different sources? It just doesn't make any sense to me.