es() / 60));
        if (delta > 12) {
          delta = 24 - delta;
        }
        var opacity = 0.75 * (1 - delta / 12);
        return new ol.style.Style({
          fill: new ol.style.Fill({
            color: [0xff, 0xff, 0x33, opacity]
          }),
          stroke: new ol.style.Stroke({
            color: '#ffffff'
          })
        });
      };

      var vector = new ol.layer.Vector({
        source: new ol.source.Vector({
          url: 'https://openlayers.org/en/v4.0.1/examples/data/kml/ti