diff --git a/docs/docs.org b/docs/docs.org
index 6360ceb..629b33a 100644
--- a/docs/docs.org
+++ b/docs/docs.org
@@ -35,6 +35,11 @@ all month in a year.
 class Weekday(models.Model):
     name = models.CharField(max_length=50)
     value = models.IntegerField()
+
+    def __str__(self):
+        return self.name
+
+
 class DayOfMonth(models.Model):
     name = models.CharField(max_length=50)
     value = models.IntegerField()
diff --git a/inventory/models.py b/inventory/models.py
index 5101f04..4ef4f61 100644
--- a/inventory/models.py
+++ b/inventory/models.py
@@ -11,6 +11,15 @@ class Device(models.Model):
 
 class Weekday(models.Model):
     name = models.CharField(max_length=50)
+    value = models.IntegerField()
+
+    def __str__(self):
+        return self.name
+
+
+class DayOfMonth(models.Model):
+    name = models.CharField(max_length=50)
+    value = models.IntegerField()
 
     def __str__(self):
         return self.name
@@ -18,6 +27,7 @@ class Weekday(models.Model):
 
 class Month(models.Model):
     name = models.CharField(max_length=50)
+    value = models.IntegerField()
 
     def __str__(self):
         return self.name