diff --git a/ultron/tools/models.py b/ultron/tools/models.py
index a02c03253d..7f9ef9c54b 100644
--- a/ultron/tools/models.py
+++ b/ultron/tools/models.py
@@ -4,7 +4,10 @@ from django.db import models
 from django.utils import timezone
 
 from datetime import date
-from .date_week_transition import get_number_of_weeks_between
+from .date_week_transition import (
+    get_number_of_weeks_between,
+    from_date_to_week_number,
+)
 import markdown
 import pendulum
 
@@ -17,6 +20,14 @@ class Seasonisable(models.Model):
     season = models.CharField(max_length=9)
     week_number = models.PositiveSmallIntegerField()
 
+    def save(self, *args, **kwargs):
+        """ Calcule les valeurs `season` et `week_number` sur base d'une date lors de l'
+        enregistrement d'un object enfant.
+        """
+        if self.date is not None:
+            self.season, self.week_number = from_date_to_week_number(self.date)
+        super().save(*args, **kwargs)
+
 
 class TemporizableQuerySet(models.QuerySet):
     """