From 2ea2d1a71e24a21a4935c124b3f98d26ea926e5e Mon Sep 17 00:00:00 2001
From: Dmitriy Shesterkin <mitri4@bk.ru>
Date: Tue, 27 Jun 2017 13:25:29 +0300
Subject: [PATCH] fix

---
 src/customer/admin.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/customer/admin.py b/src/customer/admin.py
index 8a4f5ef..86d9c60 100644
--- a/src/customer/admin.py
+++ b/src/customer/admin.py
@@ -47,8 +47,11 @@ class LicenseAdmin(admin.ModelAdmin):
     license_owner.short_description = 'Компания'
 
     def balance_days(self, obj):
-        delta = obj.date_to - timezone.now().date()
-        return delta.days
+        try:
+            delta = obj.date_to - timezone.now().date()
+            return delta.days
+        except AttributeError:
+            return '-'
 
     balance_days.short_description = 'Остаток дней'