Dates not showing in Mac Mail and Notes apps list views

Hi all. In the list views in Mail and Notes I am seeing yyyy-nn-dd instead of the dated. When I try to research this, I just get information about how to change the date format from US to European for example, rather than a fix for the date not showing.

The correct date does show on the individual item view.

Has anyone else encountered this or know of a fix?

This happens even after a reboot?

Any other non-Apple apps affected?

Can try this: In mail, try to toggle on/off “Show date/time”.


Language & Region, Advanced…, Dates. I had literally typed yyyy-mm-dd in there at some point in the past and if that ever worked, it doesn’t work now. Dragging numbers from other formats into the box and inserting the “-” does it.

Thanks !