diff --git a/biscuit/apps/chronos/views.py b/biscuit/apps/chronos/views.py
index 7d35a4212b568e00741b3fd7512028cc6ca7d9aa..0a41fcc154130a0992cb062d81bb258cbdfb378a 100644
--- a/biscuit/apps/chronos/views.py
+++ b/biscuit/apps/chronos/views.py
@@ -130,8 +130,8 @@ def lessons_day(request: HttpRequest, when: Optional[str] = None) -> HttpRespons
     context['current_head'] = _('Lessons')
     context['lessons_table'] = lessons_table
     context['day'] = day
-    context['url_prev'] = reverse('lessons_day_by_date', day + timedalta(days=-1)
-    context['url_next'] = reverse('lessons_day_by_data', day + timedalta(days=+1)
+    context['url_prev'] = reverse('lessons_day_by_date', day + timedalta(days=-1))
+    context['url_next'] = reverse('lessons_day_by_data', day + timedalta(days=1))
     context['week'] = week
     context['lesson_periods'] = lesson_periods