improved date selection behavior

rowers/views.py

@@ -15359,6 +15359,9 @@ def plannedsession_create_view(request,
 
         sessioncreateform = PlannedSessionForm(initial=forminitial)
 
+    if request.GET.get('startdate') or request.GET.get('when'):
+        startdate, enddate = get_dates_timeperiod(request)
+
     sps = get_sessions(r,startdate=startdate,enddate=enddate).exclude(
                 sessiontype='race')
     try: