measure all of the labels and take the max height

superset/assets/visualizations/nvd3_vis.js

@@ -372,11 +372,20 @@ function nvd3Vis(slice, payload) {
 
     // Hack to adjust margins to accomodate long x axis tick labels,
     // has to be done only after the chart has been rendered once,
+    // then we measure the height of the labels (they are rotated 90 degrees),
     // then we adjust the bottom margin and render again.
     if (isTimeSeries) {
-      // get height of formatted axis label
-      const xAxisHeight = $('.nv-x.nv-axis .tick text')[0].getBoundingClientRect().height;
+      //get height of formatted axis labels
+      const labelEls = $('.nv-x.nv-axis .tick text');
+      const labelHeights = labelEls.map((i) => {
+        return labelEls[i].getBoundingClientRect().height;
+      });
+      const xAxisHeight = Math.max.apply(Math, labelHeights);
+
+      // set new bottom margin to accomodate labels
       chart.margin({ bottom: xAxisHeight + 40 });
+
+      //render chart
       svg
       .datum(payload.data)
       .transition().duration(500)