diff --git a/power_plot.py b/power_plot.py
index 668f8c40d327dd849e8c26a8d097e4abc752b0c8..0675175a4bf6bd5b2ec6acbf3079cb18235b9156 100755
--- a/power_plot.py
+++ b/power_plot.py
@@ -132,6 +132,12 @@ class PowerPlotMainWindow(QMainWindow):
 
         if first_time is None:
             first_time = datetime.utcfromtimestamp(float(values[0]))
+        else:
+            while datetime.utcfromtimestamp(float(values[0])) < first_time:
+                while not values[0][0].isnumeric():
+                    line = sys.stdin.readline()
+                    values = line.split(",")
+
         self.time_dt = np.array(date2num(first_time))
 
         self.data = np.array([float(values[self.col_num])])