If you see duplicate ski days in the app, you can see more precisely why they are duplicated in the skiline.cc web portal:

In this example, the same ski pass is entered for both Snow Space and Shuttleberg Flachauwinkel. However, these areas can each display ski days from St. Johann, Kleinarl, etc., so these ski days are duplicated. This can also be seen well by the pink warning signs.

To delete the duplicate ski pass entry, you can click on the blue X on the left.