I am a Swiss citizen but I live in the US where I have a green card and pay taxes. In the US one is liable to pay taxes when one stays there for more than 180 days. However, in Switzerland, it appears that one becomes liable if one stays for over 90 days, even if one does not earn income here. We are on vacation in Switzerland and have to stay longer since one of our daughters is sick. In order to avoid exceeding 90 days, are there any good options aside from staying across the border in France, Germany, or Austria? With many thanks for any advice.