No issue: change x axis to dates instead of epoch time.

fenix-retrieval/generate_applink_data.py

@@ -203,13 +203,20 @@ def build_csv(
 
     try:
         from matplotlib import pyplot as plt
+        plot_allphs = optimize_for_plotting(allphs)
         plt.figure()
-        plt.scatter([v[0] for v in allphs], [v[1] for v in allphs])
+        plt.plot_date([v[0] for v in plot_allphs], [v[1] for v in plot_allphs])
         plt.show()
     except ImportError:
         print("Skipping print stage, cannot find matplotlib")
         return
 
+def optimize_for_plotting(data):
+    import matplotlib.dates
+    def transform_row(row):
+        matplot_date = matplotlib.dates.epoch2num(row[0])
+        return [matplot_date] + row[1:]
+    return [transform_row(list(row)) for row in data]
 
 if __name__=="__main__":
     args = csv_generation_parser().parse_args()