add:  var promotedProps = { "DTSTART": true, "DTEND": true, "DTSTAMP": true, __proto__: this.itemBasePromotedProps }; this.importUnpromotedProperties(event, promotedProps); 
context:     set icalString(value) {        if (this.mImmutable)            throw Components.results.NS_ERROR_FAILURE;        var ical = icalFromString(value);        var event = ical.getFirstSubcomponent(Components.interfaces.calIIcalComponent.VEVENT_COMPONENT);        if (!event)            throw Components.results.NS_ERROR_INVALID_ARG;        this.setItemBaseFromICS(event);        this.mapPropsFromICS(event, this.icsEventPropMap);        this.mIsAllDay = this.mStartDate && this.mStartDate.isDate;    },
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/c384132735fca7e508def655dc686043010b66fc/calEvent.js/clean/calendar/base/src/calEvent.js