code: function formatTime(el) {
      // retrieve format settings from attributes
      var options = {
        hour: el.getAttribute('hour'),
        minute: el.getAttribute('minute'),
        second: el.getAttribute('second')
      };
  
      // remove unset format attributes
      for (var opt in options) {
        if (!options[opt]) {
          delete options[opt];
        }
      }
  
      // no time format attributes provided
      if (Object.keys(options).length === 0) {
        return;
      }
  
      var formatter = makeFormatter(options);
      if (formatter) {
        // locale-aware formatting of 24 or 12 hour times
        return formatter.format(el._date);
      } else {
        // fall back to strftime for non-Intl browsers
        var timef = options.second ? '%H:%M:%S' : '%H:%M';
        return strftime(el._date, timef);
      }
    }
docs: Private: Format a time according to the `hour`, `minute`, and `second` attribute values.  el - The local-time element to format.  Returns a time String or null if no time formats are provided.