Incorrect conversion of JavaScript date from C++

See attached project. I'm in CET (UTC+1), so it is incorrectly assuming local time.

QML from the project:

import QtQuick 2.0
import test 1.0

Item {
    id: root

    QuickDate {
        Component.onCompleted: {
            console.log("  actual date = " + date.toUTCString());
            console.log("expected date = " + new Date("Thu, 01 Jan 1970 00:00:00 GMT").toUTCString());
        }
    }
}

Output:

actual date = Wed, 31 Dec 1969 23:00:00 GMT
expected date = Thu, 01 Jan 1970 00:00:00 GMT

This seems to be because a QDateTime object is constructed from the QDate object using the constructor that will set the timeSpec to Qt::LocalTime.