code: function utc_offset() {
        if (this.zone == ICAL.Timezone.localTimezone ||
            this.zone == ICAL.Timezone.utcTimezone) {
          return 0;
        } else {
          return this.zone.utcOffset(this);
        }
      }
docs: Calculates the UTC offset of the current date/time in the timezone it is
  in.
  
  @return {Number}     UTC offset in seconds