reading in utf-8 file (javascript XMLHttpRequest) gives bad european characters

Probably your file is not in UTF-8 then try this from javascript:

var request = new XMLHttpRequest();
request.open("GET", path, false);
request.overrideMimeType('text/xml; charset=iso-8859-1');

I'm having the same issue and I fixed in this way.

If you serve the js file containing the spanish days as UTF-8 and the if is NOT saved as UTF-8 it WONT work.

Save the file in your IDE as UTF-8 (ie. eclipse default for js files will be cp1252) and also serve it as UTF-8 char encoding.

If your app is java, do a filter with this code:

response.setCharacterEncoding("UTF-8");

have a good one