diff --git a/src/Entity/Timesheet.php b/src/Entity/Timesheet.php
index 80e80a88..de70c97d 100644
--- a/src/Entity/Timesheet.php
+++ b/src/Entity/Timesheet.php
@@ -572,7 +572,7 @@ class Timesheet implements EntityWithMetaFields, ExportItemInterface
     /**
      * @return string
      */
-    public function getTimezone(): string
+    public function getTimezone(): ?string
     {
         return $this->timezone;
     }
diff --git a/src/Timesheet/TimesheetService.php b/src/Timesheet/TimesheetService.php
index 801d98e9..75f99b94 100644
--- a/src/Timesheet/TimesheetService.php
+++ b/src/Timesheet/TimesheetService.php
@@ -148,6 +148,7 @@ final class TimesheetService
         $this->repository->begin();
         try {
             $this->validateTimesheet($timesheet);
+            $this->fixTimezone($timesheet);
 
             $this->dispatcher->dispatch(new TimesheetCreatePreEvent($timesheet));
             $this->repository->save($timesheet);
@@ -187,6 +188,8 @@ final class TimesheetService
         }
         */
 
+        $this->fixTimezone($timesheet);
+
         $this->dispatcher->dispatch(new TimesheetUpdatePreEvent($timesheet));
         $this->repository->save($timesheet);
         $this->dispatcher->dispatch(new TimesheetUpdatePostEvent($timesheet));
@@ -263,6 +266,21 @@ final class TimesheetService
         }
     }
 
+    /**
+     * Makes sure, that the timesheet record has the timezone of the user.
+     *
+     * This fixes #1442 and prevents a wrong time if a teamlead edits the
+     * timesheet for an employee living in another timezone.
+     *
+     * @param Timesheet $timesheet
+     */
+    private function fixTimezone(Timesheet $timesheet)
+    {
+        if (null !== ($timezone = $timesheet->getTimezone()) && $timezone !== $timesheet->getUser()->getTimezone()) {
+            $timesheet->setTimezone($timesheet->getUser()->getTimezone());
+        }
+    }
+
     /**
      * Stops active records if more than allowed are running for the timesheet user.
      *
diff --git a/tests/Timesheet/TimesheetServiceTest.php b/tests/Timesheet/TimesheetServiceTest.php
index 47cc2dda..6873c174 100644
--- a/tests/Timesheet/TimesheetServiceTest.php
+++ b/tests/Timesheet/TimesheetServiceTest.php
@@ -11,6 +11,7 @@ namespace App\Tests\Timesheet;
 
 use App\Configuration\TimesheetConfiguration;
 use App\Entity\Timesheet;
+use App\Entity\User;
 use App\Event\TimesheetCreatePostEvent;
 use App\Event\TimesheetCreatePreEvent;
 use App\Event\TimesheetDeleteMultiplePreEvent;
@@ -138,6 +139,50 @@ class TimesheetServiceTest extends TestCase
         $sut->saveNewTimesheet($newTimesheet);
     }
 
+    public function testSaveNewTimesheetFixesTimezone()
+    {
+        $user = new User();
+        $user->setTimezone('Europe/Paris');
+
+        $begin = new \DateTime('now', new \DateTimeZone('Africa/Casablanca'));
+        $timesheet = new Timesheet();
+
+        $timesheet->setBegin($begin);
+        self::assertEquals('Africa/Casablanca', $timesheet->getTimezone());
+
+        $timesheet->setUser($user);
+        self::assertEquals('Africa/Casablanca', $timesheet->getTimezone());
+
+        $authorizationChecker = $this->createMock(AuthorizationCheckerInterface::class);
+        $authorizationChecker->expects($this->once())->method('isGranted')->willReturn(true);
+        $sut = $this->getSut($authorizationChecker);
+
+        $sut->saveNewTimesheet($timesheet);
+
+        self::assertEquals('Europe/Paris', $timesheet->getTimezone());
+    }
+
+    public function testUpdateTimesheetFixesTimezone()
+    {
+        $user = new User();
+        $user->setTimezone('Europe/Paris');
+
+        $begin = new \DateTime('now', new \DateTimeZone('Africa/Casablanca'));
+        $timesheet = new Timesheet();
+
+        $timesheet->setBegin($begin);
+        self::assertEquals('Africa/Casablanca', $timesheet->getTimezone());
+
+        $timesheet->setUser($user);
+        self::assertEquals('Africa/Casablanca', $timesheet->getTimezone());
+
+        $sut = $this->getSut();
+
+        $sut->updateTimesheet($timesheet);
+
+        self::assertEquals('Europe/Paris', $timesheet->getTimezone());
+    }
+
     public function testCannotRestartedPersistedTimesheet()
     {
         $timesheet = $this->createMock(Timesheet::class);