diff --git a/accounting/models.py b/accounting/models.py
index b6a60eb..864e82b 100644
--- a/accounting/models.py
+++ b/accounting/models.py
@@ -102,7 +102,12 @@ class Transaction(models.Model):
     def is_balanced(self, value):
         self._is_balanced = value
 
-    _has_order_hole = None
+    @property
+    def has_many_same_day(self):
+        """whether there are more than one transactions at this day,
+        so that the user can sort their orders. """
+        return Transaction.objects.filter(
+            date=self.date).count() > 1
 
     @property
     def has_order_hole(self):