diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index 4ff0fe18..48f4556d 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -195,7 +195,7 @@ def join_workouts(r,ids,title='Joined Workout',
 
 
     # reorder in chronological order
-    ws = Workout.objects.filter(id__in=ids).order_by("date", "starttime")
+    ws = Workout.objects.filter(id__in=ids).order_by("startdatetime")
 
     if not parent:
         parent = ws[0]