diff --git a/src/Chamilo/CoreBundle/Entity/Session.php b/src/Chamilo/CoreBundle/Entity/Session.php
index b48c16c8e7..15db3db5bc 100644
--- a/src/Chamilo/CoreBundle/Entity/Session.php
+++ b/src/Chamilo/CoreBundle/Entity/Session.php
@@ -98,14 +98,14 @@ class Session
      *
      * @ORM\Column(name="date_start", type="date", nullable=false)
      */
-    private $dateStart;
+    //private $dateStart;
 
     /**
      * @var \DateTime
      *
      * @ORM\Column(name="date_end", type="date", nullable=false)
      */
-    private $dateEnd;
+    //private $dateEnd;
 
     /**
      * @var boolean
@@ -145,42 +145,42 @@ class Session
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="display_start_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="display_start_date", type="datetime", nullable=true, unique=false)
      */
     private $displayStartDate;
 
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="display_end_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="display_end_date", type="datetime", nullable=true, unique=false)
      */
     private $displayEndDate;
 
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="access_start_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="access_start_date", type="datetime", nullable=true, unique=false)
      */
     private $accessStartDate;
 
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="access_end_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="access_end_date", type="datetime", nullable=true, unique=false)
      */
     private $accessEndDate;
 
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="coach_access_start_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="coach_access_start_date", type="datetime", nullable=true, unique=false)
      */
     private $coachAccessStartDate;
 
     /**
      * @var \DateTime
      *
-     * @ORM\Column(name="coach_access_end_date", type="datetime", nullable=false, unique=false)
+     * @ORM\Column(name="coach_access_end_date", type="datetime", nullable=true, unique=false)
      */
     private $coachAccessEndDate;
 
@@ -616,51 +616,6 @@ class Session
         return $this->nbrClasses;
     }
 
-    /**
-     * Set dateStart
-     *
-     * @param \DateTime $dateStart
-     * @return Session
-     */
-    public function setDateStart($dateStart)
-    {
-        $this->dateStart = $dateStart;
-
-        return $this;
-    }
-
-    /**
-     * Get dateStart
-     *
-     * @return \DateTime
-     */
-    public function getDateStart()
-    {
-        return $this->dateStart;
-    }
-
-    /**
-     * Set dateEnd
-     *
-     * @param \DateTime $dateEnd
-     * @return Session
-     */
-    public function setDateEnd($dateEnd)
-    {
-        $this->dateEnd = $dateEnd;
-
-        return $this;
-    }
-
-    /**
-     * Get dateEnd
-     *
-     * @return \DateTime
-     */
-    public function getDateEnd()
-    {
-        return $this->dateEnd;
-    }
 
     /**
      * Set nbDaysAccessBeforeBeginning
diff --git a/src/Chamilo/CoreBundle/Migrations/Schema/V110/Version20150528103216.php b/src/Chamilo/CoreBundle/Migrations/Schema/V110/Version20150528103216.php
new file mode 100644
index 0000000000..4517263cb3
--- /dev/null
+++ b/src/Chamilo/CoreBundle/Migrations/Schema/V110/Version20150528103216.php
@@ -0,0 +1,44 @@
+<?php
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\CoreBundle\Migrations\Schema\V110;
+
+use Chamilo\CoreBundle\Migrations\AbstractMigrationChamilo;
+use Doctrine\DBAL\Schema\Schema;
+
+/**
+ * Session date changes
+ */
+class Version20150528103216 extends AbstractMigrationChamilo
+{
+    /**
+     * @param Schema $schema
+     */
+    public function up(Schema $schema)
+    {
+        $this->addSql('UPDATE session SET access_start_date = date_start');
+        $this->addSql("UPDATE session SET access_end_date = CONVERT(CONCAT(date_end, ' 23:59:59'), DATETIME)");
+
+        $this->addSql('UPDATE session SET coach_access_start_date = CONVERT(DATE_SUB(date_start, INTERVAL nb_days_access_before_beginning DAY), DATETIME) ');
+        $this->addSql('UPDATE session SET coach_access_start_date = NULL WHERE nb_days_access_before_beginning = 0');
+
+        $this->addSql('UPDATE session SET coach_access_end_date = CONVERT(DATE_ADD(date_end, INTERVAL nb_days_access_after_end DAY), DATETIME) ');
+        $this->addSql('UPDATE session SET coach_access_end_date = NULL WHERE nb_days_access_after_end = 0');
+
+        $this->addSql('UPDATE session SET display_start_date = access_start_date');
+        $this->addSql('UPDATE session SET display_end_date = access_end_date');
+    }
+
+    /**
+     * @param Schema $schema
+     */
+    public function down(Schema $schema)
+    {
+        $this->addSql('ALTER TABLE session DROP access_start_date');
+        $this->addSql('ALTER TABLE session DROP access_end_date');
+        $this->addSql('ALTER TABLE session DROP coach_access_start_date');
+        $this->addSql('ALTER TABLE session DROP coach_access_end_date');
+        $this->addSql('ALTER TABLE session DROP display_start_date');
+        $this->addSql('ALTER TABLE session DROP display_end_date');
+    }
+}