diff --git a/app/Http/Controllers/TimeTrackerController.php b/app/Http/Controllers/TimeTrackerController.php
index ef5fe25..d92d823 100644
--- a/app/Http/Controllers/TimeTrackerController.php
+++ b/app/Http/Controllers/TimeTrackerController.php
@@ -53,7 +53,7 @@ class TimeTrackerController extends Controller
      */
     public function show(TimeTracker $timeTracker)
     {
-        //
+        return response()->json(new TimeTrackerResource($timeTracker->load('toDo')));
     }
 
     /**
diff --git a/app/Http/Resources/ToDoResource.php b/app/Http/Resources/ToDoResource.php
index 9826013..408246e 100644
--- a/app/Http/Resources/ToDoResource.php
+++ b/app/Http/Resources/ToDoResource.php
@@ -19,7 +19,7 @@ class ToDoResource extends JsonResource
             'user_id' => $this->user_id,
             'name' => $this->name,
             'description' => $this->description,
-            'checked' => $this->checked,
+            'checked' => $this->checked?->format('Y-m-d H:i:s'),
             'duration' => $this->duration,
         ];
     }
diff --git a/app/Models/ToDo.php b/app/Models/ToDo.php
index c2b59ee..0c52900 100644
--- a/app/Models/ToDo.php
+++ b/app/Models/ToDo.php
@@ -17,6 +17,10 @@ class ToDo extends Model
         'description',
     ];
 
+    protected $casts = [
+        'checked' => 'datetime',
+    ];
+
     public function user(): BelongsTo
     {
         return $this->belongsTo(User::class);
diff --git a/tests/Feature/TimeTrackerTest.php b/tests/Feature/TimeTrackerTest.php
index 7285663..bd85050 100644
--- a/tests/Feature/TimeTrackerTest.php
+++ b/tests/Feature/TimeTrackerTest.php
@@ -54,6 +54,27 @@ test('user has no content response if not current time tracker', function () {
         ->assertNoContent();
 });
 
+test('user can retrieve a time tracker', function () {
+    Sanctum::actingAs($user = User::factory()->create());
+    $toDo = ToDo::factory()->create(['user_id' => $user->id, 'checked' => null]);
+    $timeTracker = $toDo->timeTrackers()->create([
+        'start_at' => now()->subMinutes(20),
+        'end_at' => now()->subMinutes(10),
+    ]);
+
+    $this->get('/api/time-trackers/'.$timeTracker->id)
+        ->assertOk()
+        ->assertJson([
+            'id' => $timeTracker->id,
+            'start_at' => now()->subMinutes(20),
+            'end_at' => now()->subMinutes(10),
+            'to_do' => [
+                'id' => $toDo->id,
+                'user_id' => $user->id,
+            ],
+        ]);
+});
+
 test('user can stop current time tracker', function () {
     Sanctum::actingAs($user = User::factory()->create());
     $toDo = ToDo::factory()->create(['user_id' => $user->id, 'checked' => null]);
@@ -115,3 +136,18 @@ test('user can update a time tracker', function () {
 
     expect($toDo->refresh())->duration->toBe(660);
 });
+
+test('user can retrieve time trackers of a todo', function () {
+    Sanctum::actingAs($user = User::factory()->create());
+    $toDo = ToDo::factory()->create(['user_id' => $user->id, 'duration' => 600, 'checked' => null]);
+    for ($i = 10; $i > 0; $i--) {
+        $toDo->timeTrackers()->create([
+            'start_at' => now()->subMinutes(20 + $i * 10),
+            'end_at' => now()->subMinutes(10 + $i * 10),
+        ]);
+    }
+
+    $this->get("/api/todos/{$toDo->id}/time-trackers")
+        ->assertOk()
+        ->assertJsonCount(10);
+});
diff --git a/tests/Feature/ToDoTest.php b/tests/Feature/ToDoTest.php
index 968695d..cfaa04b 100644
--- a/tests/Feature/ToDoTest.php
+++ b/tests/Feature/ToDoTest.php
@@ -96,9 +96,8 @@ test('an user can update a to do', function () {
 
     $toDo = $toDos[rand(0, 9)];
 
-    $response = $this->put('api/todos/'.$toDo->id, ['name' => 'update test']);
-
-    $response->assertOk()
+    $this->put('api/todos/'.$toDo->id, ['name' => 'update test'])
+        ->assertOk()
         ->assertJson([
             'id' => $toDo->id,
             'user_id' => $toDo->user_id,
@@ -108,6 +107,15 @@ test('an user can update a to do', function () {
 
     expect(ToDo::find($toDo->id))
         ->name->toBe('update test');
+
+    $this->put('api/todos/'.$toDo->id, ['checked' => true])
+        ->assertOk()
+        ->assertJson([
+            'id' => $toDo->id,
+            'user_id' => $toDo->user_id,
+            'name' => 'update test',
+            'checked' => now()->format('Y-m-d H:i:s'),
+        ]);
 });
 
 test('an user can delete a to do', function () {