Getting UTC timestamps of iCal with Timezone using the mozilla-comm/ical.js lib

gistfile1.js

var vtimezones = comp.getAllSubcomponents("vtimezone");
_.each(vtimezones, function (vtimezone) {
    //Si timezone está registrada
    if (!(ICAL.TimezoneService.has(
        vtimezone.getFirstPropertyValue("tzid")))) {
        ICAL.TimezoneService.register(vtimezone);
    }
});