fix

rowers/models.py

@@ -3697,13 +3697,22 @@ class Workout(models.Model):
 
     def __str__(self):
 
+        try:
+            dates = self.date.strftime('%Y-%m-%d')
+        except AttributeError:
+            dates = ''
+        try:
+            durations = self.duration.strftime("%H:%M:%S"),
+        except AttributeError:
+            durations = ''
+
         elements = dict(
-            date = self.date.strftime('%Y-%m-%d'),
+            date = dates,
             name = self.name,
             distance = str(self.distance)+'m',
             ownerfirst = self.user.user.first_name,
             ownerlast = self.user.user.last_name,
-            duration = self.duration.strftime("%H:%M:%S"),
+            duration = durations,
             boattype = self.boattype,
             workouttype = self.workouttype,
             seatnumber = 'seat '+str(self.seatnumber),