public function getAvailableTimesets()
    {
        // build array with localized names
        if (!isset(self::$timesetNames)) {
            self::$timesetNames = [
                $this->translator->_('standard_time'),
                $this->translator->_('swatch_time'),
                $this->translator->_('iso_time'),
            ];
        }

        // return the names of the timesets
        return self::$timesetNames;
    }