Timezone not working when using visualize.js

While using visualize.js for embedding we were able to see that the timezone parameter doesn't affect the report date values. At the same time when logging into Jaspersoft web application directly, after selecting a time zone the same report values (eg: Audit Report) are shown in the time zone selected in the login screen. This does not seem to be the case with visualize.js, it is just displaying the report in the server timezone inspite of passing the timezone paramter. Is this is a bug? Sample code, given below

visualize(
                            {
                              auth: {
                                token: preAuthToken,
                                preAuth: true,
                                tokenName: "jtkn",
                                timezone: "America/New_York"
                              }
                            },
                            function(v) {

});