diff --git a/src/Bundle/ChillCalendarBundle/Exception/UserAbsenceSyncException.php b/src/Bundle/ChillCalendarBundle/Exception/UserAbsenceSyncException.php
index b46c93976..558774fc5 100644
--- a/src/Bundle/ChillCalendarBundle/Exception/UserAbsenceSyncException.php
+++ b/src/Bundle/ChillCalendarBundle/Exception/UserAbsenceSyncException.php
@@ -13,8 +13,8 @@ namespace Chill\CalendarBundle\Exception;
 
 class UserAbsenceSyncException extends \LogicException
 {
-    public function __construct(string $message = "", int $code = 20230706)
+    public function __construct(string $message = "", int $code = 20230706, ?\Throwable $previous = null)
     {
-        parent::__construct($message, $code);
+        parent::__construct($message, $code, $previous);
     }
 }
diff --git a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReader.php b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReader.php
index b79a55052..83376528f 100644
--- a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReader.php
+++ b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReader.php
@@ -21,7 +21,7 @@ use Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface;
 use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
 
-readonly class MSUserAbsenceReader
+final readonly class MSUserAbsenceReader implements MSUserAbsenceReaderInterface
 {
     public function __construct(
         private HttpClientInterface $machineHttpClient,
diff --git a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReaderInterface.php b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReaderInterface.php
new file mode 100644
index 000000000..a918bb7ea
--- /dev/null
+++ b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceReaderInterface.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\CalendarBundle\RemoteCalendar\Connector\MSGraph;
+
+use Chill\MainBundle\Entity\User;
+
+interface MSUserAbsenceReaderInterface
+{
+    /**
+     * @throw UserAbsenceSyncException when the data cannot be reached or is not valid from microsoft
+     */
+    public function isUserAbsent(User $user): bool|null;
+}
diff --git a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSync.php b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSync.php
new file mode 100644
index 000000000..aaa06a64b
--- /dev/null
+++ b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSync.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\CalendarBundle\RemoteCalendar\Connector\MSGraph;
+
+use Chill\MainBundle\Entity\User;
+use Symfony\Component\Clock\ClockInterface;
+
+readonly class MSUserAbsenceSync
+{
+    public function __construct(
+        private MSUserAbsenceReaderInterface $absenceReader,
+        private ClockInterface $clock,
+    ) {
+    }
+
+    public function syncUserAbsence(User $user): void
+    {
+        $absence = $this->absenceReader->isUserAbsent($user);
+
+        if (null === $absence) {
+            return;
+        }
+
+        if ($absence === $user->isAbsent()) {
+            // nothing to do
+            return;
+        }
+
+        if ($absence) {
+            $user->setAbsenceStart($this->clock->now());
+        } else {
+            $user->setAbsenceStart(null);
+        }
+    }
+}
diff --git a/src/Bundle/ChillCalendarBundle/Tests/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSyncTest.php b/src/Bundle/ChillCalendarBundle/Tests/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSyncTest.php
new file mode 100644
index 000000000..ddd92086d
--- /dev/null
+++ b/src/Bundle/ChillCalendarBundle/Tests/RemoteCalendar/Connector/MSGraph/MSUserAbsenceSyncTest.php
@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\CalendarBundle\Tests\RemoteCalendar\Connector\MSGraph;
+
+use Chill\CalendarBundle\RemoteCalendar\Connector\MSGraph\MSUserAbsenceReader;
+use Chill\CalendarBundle\RemoteCalendar\Connector\MSGraph\MSUserAbsenceReaderInterface;
+use Chill\CalendarBundle\RemoteCalendar\Connector\MSGraph\MSUserAbsenceSync;
+use Chill\MainBundle\Entity\User;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+use Symfony\Component\Clock\MockClock;
+
+/**
+ * @internal
+ * @coversNothing
+ */
+class MSUserAbsenceSyncTest extends TestCase
+{
+    use ProphecyTrait;
+
+    /**
+     * @dataProvider provideDataTestSyncUserAbsence
+     */
+    public function testSyncUserAbsence(User $user, ?bool $absenceFromMicrosoft, bool $expectedAbsence, ?\DateTimeImmutable $expectedAbsenceStart, string $message): void
+    {
+        $userAbsenceReader = $this->prophesize(MSUserAbsenceReaderInterface::class);
+        $userAbsenceReader->isUserAbsent($user)->willReturn($absenceFromMicrosoft);
+
+        $clock = new MockClock(new \DateTimeImmutable('2023-07-01T12:00:00'));
+
+        $syncer = new MSUserAbsenceSync($userAbsenceReader->reveal(), $clock);
+
+        $syncer->syncUserAbsence($user);
+
+        self::assertEquals($expectedAbsence, $user->isAbsent(), $message);
+        self::assertEquals($expectedAbsenceStart, $user->getAbsenceStart(), $message);
+    }
+
+    public function provideDataTestSyncUserAbsence(): iterable
+    {
+        yield [new User(), false, false, null, "user present remains present"];
+        yield [new User(), true, true, new \DateTimeImmutable('2023-07-01T12:00:00'), "user present becomes absent"];
+
+        $user = new User();
+        $user->setAbsenceStart($abs = new \DateTimeImmutable("2023-07-01T12:00:00"));
+        yield [$user, true, true, $abs, "user absent remains absent"];
+
+        $user = new User();
+        $user->setAbsenceStart($abs = new \DateTimeImmutable("2023-07-01T12:00:00"));
+        yield [$user, false, false, null, "user absent becomes present"];
+
+        yield [new User(), null, false, null, "user not syncable: presence do not change"];
+
+        $user = new User();
+        $user->setAbsenceStart($abs = new \DateTimeImmutable("2023-07-01T12:00:00"));
+        yield [$user, null, true, $abs, "user not syncable: absence do not change"];
+    }
+}