I have a calendar component and when I view it monthly or daily items appear to display correctly.
However when I view in weekly mode, Events on the Sunday are not displayed.
I have tried Mobile and Desktop and get the same problem in both.
Here is a Monthly View
Here is the Daily View and you can see the event is displaying
This is the Weekly View and you can see the Event on Sunday is not displayed:
I have seen other Visual issues reported on the calendar but believe this to be different since it related to a specific day or perhaps being the last day of week, but is a problem if people have events on the day and they do not show up.