diff --git a/smash/web/models/visit.py b/smash/web/models/visit.py
index 7025a26c4de156f3097e164059bec46207fb4465..4e96574d24dfeb8569f8a01b6e3f2f1aeb2e979b 100644
--- a/smash/web/models/visit.py
+++ b/smash/web/models/visit.py
@@ -9,6 +9,8 @@ from django.dispatch import receiver
 from web.models.constants import BOOL_CHOICES, SUBJECT_TYPE_CHOICES_CONTROL
 from web.models import Study
 
+import logging
+logger = logging.getLogger(__name__)
 
 class Visit(models.Model):
 
@@ -79,10 +81,12 @@ class Visit(models.Model):
             
             time_to_next_visit = relativedelta(**args) * (follow_up_number - 1) #calculated from first visit
 
+            logger.warn('new visit: {} {} {}'.format(args, relativedelta(**args), time_to_next_visit))
+
             Visit.objects.create(
                 subject=self.subject,
                 datetime_begin=visit_started + time_to_next_visit,
-                datetime_end=visit_started + time_to_next_visit + datetime.timedelta(days=study.default_visit_duration_in_months)
+                datetime_end=visit_started + time_to_next_visit + relativedelta(months=study.default_visit_duration_in_months)
             )