diff --git a/biscuit/apps/chronos/views.py b/biscuit/apps/chronos/views.py
index 92d95446f0643864413854efa1baa828a01555ad..1e5694ce16afd0edb8f2f8a820de83004bfc5706 100644
--- a/biscuit/apps/chronos/views.py
+++ b/biscuit/apps/chronos/views.py
@@ -1,6 +1,7 @@
 from collections import OrderedDict
 
 from django.contrib.auth.decorators import login_required
+from django.db.models import Max, Min
 from django.http import HttpRequest, HttpResponse
 from django.shortcuts import redirect, render
 from django.urls import reverse