diff --git a/src/sherlock/models.py b/src/sherlock/models.py
index 1e2f7b2..394811b 100644
--- a/src/sherlock/models.py
+++ b/src/sherlock/models.py
@@ -19,7 +19,7 @@ class Gauge(models.Model):
         ordering = ['category']
 
 
-class Diff(object):
+class DiffMesure(object):
     def __init__(self, mesure_1, mesure_2):
         self.increase = abs(mesure_1.diff(mesure_2))
         self.timedelta = abs(mesure_1.moment - mesure_2.moment)
@@ -42,7 +42,7 @@ class Mesure(models.Model):
     objects = MesureManager()
 
     def __str__(self):
-        return "{} {}".format(self.moment, self.value)
+        return "{} {}".format(self.moment.strftime('%Y-%m-%d %H:%M'), self.value)
 
     def diff(self, other_mesure):
         if self.category != other_mesure.category:
diff --git a/src/sherlock/tests.py b/src/sherlock/tests.py
index ad003c2..236a85b 100644
--- a/src/sherlock/tests.py
+++ b/src/sherlock/tests.py
@@ -1,11 +1,11 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 
 
 from django.test import TestCase
 from django.utils import timezone
 
 
-from .models import Category, Gauge, Mesure
+from .models import Category, Gauge, Mesure, DiffMesure
 
 
 class TestCategoryModel(TestCase):
@@ -50,6 +50,23 @@ class TestGaugeModel(TestCase):
         self.assertEqual(1, len(gauge_1.mesures.all()))
 
 
+class TestDiffMesure(TestCase):
+    def setUp(self):
+        d1 = timezone.make_aware(datetime(2016, 1, 1))
+        d2 = timezone.make_aware(datetime(2016, 2, 1))
+
+        self.m1 = Mesure.objects.create_with_deps(d1, 0.001, 'undefined', 'eau')
+        self.m2 = Mesure.objects.create_with_deps(d2, 0.002, 'undefined', 'eau')
+
+    def test_init(self):
+        diff = DiffMesure(self.m1, self.m2)
+
+        td = timedelta(days=31)
+
+        self.assertEqual(0.001, diff.increase)
+        self.assertEqual(td, diff.timedelta)
+
+
 class TestMesureManager(TestCase):
     def test_create_with_deps(self):
         d1 = timezone.make_aware(datetime(2016, 1, 1))
@@ -80,12 +97,16 @@ class TestMesureModel(TestCase):
 
         d1 = timezone.make_aware(datetime(2016, 1, 1))
         d2 = timezone.make_aware(datetime(2016, 1, 2))
-        d3 = timezone.make_aware(datetime(2016, 1, 3))
+        d3 = timezone.make_aware(datetime(2016, 1, 3, 23, 58))
 
         self.mesure_1 = Mesure.objects.create(moment=d1, value=0.001, gauge=self.gauge_1)
         self.mesure_2 = Mesure.objects.create(moment=d2, value=0.002, gauge=self.gauge_2)
         self.mesure_3 = Mesure.objects.create(moment=d3, value=0.003, gauge=self.gauge_1)
 
+    def test_str(self):
+        self.assertEqual('2016-01-01 00:00 0.001', str(self.mesure_1))
+        self.assertEqual('2016-01-03 23:58 0.003', str(self.mesure_3))
+
     def test_category_property(self):
         self.assertEqual(self.cat_water, self.mesure_1.category)