I tried to replicate the behavior, but I can’t seem to find a way to do so.
I would recommend that you try a few things:
- Within the desktop/browser application, duplicate the calendar view and see if the dates display the same way.
- If that doesn’t work, then try to create a new calendar view altogether (without any of the same settings, filters, sorting, etc.) and see if it persists.
Worst case scenario, a support ticket might shed some light on the behavior, as I wasn’t able to find anything in the support articles relating to this behavior.