http://track-chinapost.com/startairmail.php shows the parcel was shipped to Switzerland on Mar 16. It is still in China waiting for airline space to Switzerland.

China government has cancelled all international airlines to stop cover-19 spreading. China Post has no shipping space to send parcels abroad. You need wait some more time.

Right now it is difficult to predict accurate arrival time. It should be after the covid19 crisis ends and international airline back to normal.