diff --git a/date_range/models/date_range.py b/date_range/models/date_range.py
index a88128013..9ea9f84ed 100644
--- a/date_range/models/date_range.py
+++ b/date_range/models/date_range.py
@@ -55,6 +55,31 @@ class DateRange(models.Model):
                     _('The Company in the Date Range and in '
                       'Date Range Type must be the same.'))
 
+    @api.constrains('parent_id', 'date_start', 'date_end')
+    def _validate_child_range(self):
+        for this in self:
+            if not this.parent_id:
+                continue
+            start = this.parent_id.date_start <= this.date_start
+            end = this.parent_id.date_end >= this.date_end
+            child_range = start and end
+            if not child_range:
+                if (not start) and end:
+                    text = _("Start dates are not compatible (%s < %s)") % (
+                        this.date_start, this.parent_id.date_start)
+                elif (not end) and start:
+                    text = _("End dates are not compatible (%s > %s)") % (
+                        this.date_end, this.parent_id.date_end)
+                else:
+                    text = _("%s range not in %s - %s") % (
+                        this.name,
+                        this.parent_id.date_start,
+                        this.parent_id.date_end,
+                    )
+                raise ValidationError(
+                    _("%s not a subrange of %s: " + text) % (
+                        this.name, this.parent_id.name))
+
     @api.constrains('type_id', 'date_start', 'date_end', 'company_id')
     def _validate_range(self):
         for this in self:
diff --git a/date_range/tests/test_date_range.py b/date_range/tests/test_date_range.py
index 55912fc53..d19ff6fed 100644
--- a/date_range/tests/test_date_range.py
+++ b/date_range/tests/test_date_range.py
@@ -138,21 +138,52 @@ class DateRangeTest(TransactionCase):
             'date_end': '2018-12-31',
             'type_id': self.type.id,
         })
-        # Check here that a validation error is thrown
-        # when parent and child have same type_id
-        with self.assertRaises(ValidationError):
-            self.date_range.create({
-                'name': 'FS2018-period1',
-                'date_start': '2018-01-01',
-                'date_end': '2018-04-30',
-                'type_id': self.type.id,
-                'parent_id': parent.id,
-            })
         type_block = date_range_type.create({
             'name': 'FS2018-type_block',
             'company_id': False,
             'allow_overlap': False,
         })
+        # Check here all three validation errors thrown
+        # when child range is not a subrange of parent
+        with self.assertRaises(ValidationError) as cm, self.env.cr.savepoint():
+            self.date_range.create({
+                'name': 'FS2018-period1',
+                'date_start': '2018-06-06',
+                'date_end': '2019-01-02',
+                'type_id': type_block.id,
+                'parent_id': parent.id,
+            })
+        self.assertEqual(
+            cm.exception.name,
+            'FS2018-period1 not a subrange of FS2018: '
+            'End dates are not compatible (2019-01-02 > 2018-12-31)'
+        )
+        with self.assertRaises(ValidationError) as cm, self.env.cr.savepoint():
+            self.date_range.create({
+                'name': 'FS2018-period1',
+                'date_start': '2017-06-06',
+                'date_end': '2018-01-02',
+                'type_id': type_block.id,
+                'parent_id': parent.id,
+            })
+        self.assertEqual(
+            cm.exception.name,
+            'FS2018-period1 not a subrange of FS2018: '
+            'Start dates are not compatible (2017-06-06 < 2018-01-01)'
+        )
+        with self.assertRaises(ValidationError) as cm, self.env.cr.savepoint():
+            self.date_range.create({
+                'name': 'FS2018-period1',
+                'date_start': '2017-06-06',
+                'date_end': '2019-01-02',
+                'type_id': type_block.id,
+                'parent_id': parent.id,
+            })
+        self.assertEqual(
+            cm.exception.name,
+            'FS2018-period1 not a subrange of FS2018: '
+            'FS2018-period1 range not in 2018-01-01 - 2018-12-31'
+        )
         period1 = self.date_range.create({
             'name': 'FS2018-period1',
             'date_start': '2018-01-01',