diff --git a/addons/point_of_sale/report/pos_details_summary.py b/addons/point_of_sale/report/pos_details_summary.py
index a9e2ac689d3..579b28ca6ca 100644
--- a/addons/point_of_sale/report/pos_details_summary.py
+++ b/addons/point_of_sale/report/pos_details_summary.py
@@ -20,6 +20,7 @@
 ##############################################################################
 
 import time
+import datetime
 from report import report_sxw
 
 
@@ -120,24 +121,15 @@ class pos_details_summary(report_sxw.rml_parse):
         return reduce(lambda x, o: x + len(o.lines), objects, 0)
 
     def _get_start_period(self, objects):
-        date_orders = [obj.date_order for obj in objects]
-        print "=========================",date_orders
-        min_date = min(date_orders)
-        max_date = max(date_orders)
-        print "========================",min_date
-        if min_date == max_date:
-            return '%s' % min_date
-        else:
-            return '%s' % min_date
+        date_orders = sorted([obj.date_order for obj in objects])
+        min_date = date_orders[0]
+        return '%s' % min_date
+
 
     def _get_end_period(self, objects):
         date_orders = [obj.date_order for obj in objects]
-        min_date = min(date_orders)
-        max_date = max(date_orders)
-        if min_date == max_date:
-            return '%s' % max_date
-        else:
-            return '%s' % max_date
+        max_date = date_orders[-1]
+        return '%s' % max_date
 
 
 report_sxw.report_sxw('report.pos.details_summary',