diff --git a/library/Class/WebService/C3rb.php b/library/Class/WebService/C3rb.php
index f6294a8d92cf666b800f2235421b1fe2e349cf47..d492e8cfe0e5e7da26c0fd826550f43c9dbd8f0d 100644
--- a/library/Class/WebService/C3rb.php
+++ b/library/Class/WebService/C3rb.php
@@ -42,10 +42,10 @@ class Class_WebService_C3rb extends Class_WebService_Cas2 {
 
 
   protected function _validateValue(?string $value, string $function_name) {
-    return ((($function_name == 'naissance')
-             || ($function_name=='date_fin'))
+    return ((('naissance' === $function_name)
+             || ('date_fin' === $function_name))
             && $value)
-      ? date('Y-m-d', strtotime($value))
+      ? Class_TimeSource::tryFormatDate($value)
       : $value;
   }
 }
diff --git a/library/Class/WebService/Cas3.php b/library/Class/WebService/Cas3.php
index 00e6637006737e69392e15e454b0604d30f92434..0d543949afc1f4be1d4de2e1a2587856405771a4 100644
--- a/library/Class/WebService/Cas3.php
+++ b/library/Class/WebService/Cas3.php
@@ -65,7 +65,8 @@ class Class_WebService_Cas3 extends Class_WebService_Cas2 {
     if (!$value)
       return '';
 
-    if (!(($function_name == 'naissance') ||($function_name == 'date_fin')) )
+    if (!(('naissance' === $function_name)
+          ||('date_fin' === $function_name)) )
       return $value;
 
     if (strlen($value) <= 4)
diff --git a/tests/scenarios/IdentityProvider/IdentityProviderAuthenticationC3rbTest.php b/tests/scenarios/IdentityProvider/IdentityProviderAuthenticationC3rbTest.php
index f2ccb32258a3e027c62908687a30d198fb5978ce..1cfee70570d8fdec26df6167334245bd230ed78e 100644
--- a/tests/scenarios/IdentityProvider/IdentityProviderAuthenticationC3rbTest.php
+++ b/tests/scenarios/IdentityProvider/IdentityProviderAuthenticationC3rbTest.php
@@ -212,7 +212,7 @@ class IdentityProviderAuthenticationC3rbToBokehUpdateTestCase
     <cas:attributes>
       <cas:user>myawesomeuser</cas:user>
       <cas:mail>awesome@user.fr</cas:mail>
-      <cas:birth></cas:birth>
+      <cas:birth>1973-01-23</cas:birth>
       <cas:nom>Awesome</cas:nom>
       <cas:prenom>MyEdited</cas:prenom>
       <cas:date_renouv>01/01/2024</cas:date_renouv>
@@ -259,13 +259,13 @@ class IdentityProviderAuthenticationC3rbToBokehUpdateTestCase
 
 
   /** @test */
-  public function userBirthShouldBeEmpty() {
-    $this->assertEquals('', Class_Users::getIdentity()->getNaissance());
+  public function userBirthShouldBe19730123() {
+    $this->assertEquals('1973-01-23', Class_Users::getIdentity()->getNaissance());
   }
 
 
   /** @test */
-  public function userDateFinShouldExpectation() {
+  public function userDateFinShouldBe20240101() {
     $this->assertEquals('2024-01-01', Class_Users::getIdentity()->getDateFin());
   }
 }