Date objects have incorrect timezone information in certain timezones.

Reproducable with tzdata 2015a, I have not checked other versions of tzdata.

Set timezone to America/Santiago.

In Qt Quick 2.0 enviroment, run this test:

console.log(new Date().getTimezoneOffset());
console.log(new Date());

Result:

120
Mon Feb 23 13:45:23 2015 GMT-0200

Expected result (correct in v8, QtWebKit, QtQuick 1.0):

180
Mon Feb 23 2015 13:45:23 GMT-0300 (CLST)

The local time is correct, but the timezone information is not correct.