diff --git a/src/Infra/Adapters/Directories/InMemoryEmployeeDirectory.php b/src/Infra/Adapters/Directories/InMemoryEmployeeDirectory.php
index 7728173..1d97566 100644
--- a/src/Infra/Adapters/Directories/InMemoryEmployeeDirectory.php
+++ b/src/Infra/Adapters/Directories/InMemoryEmployeeDirectory.php
@@ -91,8 +91,12 @@ final class InMemoryEmployeeDirectory implements EmployeeDirectory
             return false;
         }
 
-        if ($filter->since !== null && $employee->startDate < $filter->since) {
-            return false;
+        if ($filter->since !== null) {
+            $createdAtMatches = $employee->createdAt                                  >= $filter->since;
+            $updatedAtMatches = $employee->updatedAt !== null && $employee->updatedAt >= $filter->since;
+            if (! $createdAtMatches && ! $updatedAtMatches) {
+                return false;
+            }
         }
 
         return true;
diff --git a/tests/Unit/Infra/Adapters/Directories/InMemoryEmployeeDirectoryTest.php b/tests/Unit/Infra/Adapters/Directories/InMemoryEmployeeDirectoryTest.php
index 9a2e0db..d84a3fb 100644
--- a/tests/Unit/Infra/Adapters/Directories/InMemoryEmployeeDirectoryTest.php
+++ b/tests/Unit/Infra/Adapters/Directories/InMemoryEmployeeDirectoryTest.php
@@ -94,6 +94,68 @@ describe('InMemoryEmployeeDirectory Unit Tests', function (): void {
             ->and($result->getItems()[0]->publicEmployeeNumber->value)->toBe('00000001');
     });
 
+    it('filters employees by since date comparing against createdAt and updatedAt', function (): void {
+        // GIVEN
+        $directory = new InMemoryEmployeeDirectory();
+
+        $emp1 = new Employee(
+            publicEmployeeNumber: new ArcadiaEmployeeId('00000001'),
+            lastName: 'ALICE',
+            firstName: 'A',
+            startDate: new \DateTimeImmutable('2023-01-01'),
+            endDate: null,
+            plannedEndDate: null,
+            establishment: new EstablishmentCode('EST01'),
+            site: new SiteId('SITEO'),
+            service: new ServiceId('097'),
+            createdAt: new \DateTimeImmutable('2024-01-01'),
+            updatedAt: null,
+        );
+
+        $emp2 = new Employee(
+            publicEmployeeNumber: new ArcadiaEmployeeId('00000002'),
+            lastName: 'BOB',
+            firstName: 'B',
+            startDate: new \DateTimeImmutable('2023-01-01'),
+            endDate: null,
+            plannedEndDate: null,
+            establishment: new EstablishmentCode('EST01'),
+            site: new SiteId('SITEO'),
+            service: new ServiceId('097'),
+            createdAt: new \DateTimeImmutable('2023-01-01'),
+            updatedAt: new \DateTimeImmutable('2024-02-01'),
+        );
+
+        $emp3 = new Employee(
+            publicEmployeeNumber: new ArcadiaEmployeeId('00000003'),
+            lastName: 'CHARLIE',
+            firstName: 'C',
+            startDate: new \DateTimeImmutable('2024-06-01'),
+            endDate: null,
+            plannedEndDate: null,
+            establishment: new EstablishmentCode('EST01'),
+            site: new SiteId('SITEO'),
+            service: new ServiceId('097'),
+            createdAt: new \DateTimeImmutable('2023-01-01'),
+            updatedAt: new \DateTimeImmutable('2023-06-01'),
+        );
+
+        $directory->add($emp1, $emp2, $emp3);
+
+        $pagination = Pagination::ofPage(1, 10);
+        $sorter     = new EmployeeSorter(EmployeeSortColumn::arcadiaId, \SortDirection::Ascending);
+        $filter     = new EmployeeFilter(since: new \DateTimeImmutable('2024-01-01'));
+
+        // WHEN
+        $result = $directory->findAll($pagination, $sorter, $filter);
+
+        // THEN
+        expect($result->getTotal())->toBe(2)
+            ->and($result->getItems())->toHaveCount(2)
+            ->and($result->getItems()[0]->publicEmployeeNumber->value)->toBe('00000001')
+            ->and($result->getItems()[1]->publicEmployeeNumber->value)->toBe('00000002');
+    });
+
     it('clears all stored employees', function (): void {
         // GIVEN
         $directory  = new InMemoryEmployeeDirectory();