diff --git a/app/Domain/VacationDaysCalculator.php b/app/Domain/VacationDaysCalculator.php
new file mode 100644
index 0000000..fcbc9e8
--- /dev/null
+++ b/app/Domain/VacationDaysCalculator.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Domain;
+
+use Carbon\CarbonInterface;
+use Carbon\CarbonPeriod;
+use Illuminate\Support\Collection;
+use Toby\Eloquent\Models\YearPeriod;
+
+class VacationDaysCalculator
+{
+    public function calculateDays(YearPeriod $yearPeriod, CarbonInterface $from, CarbonInterface $to): Collection
+    {
+        $period = CarbonPeriod::create($from, $to);
+        $holidays = $yearPeriod->holidays()->pluck("date");
+
+        $validDays = collect();
+
+        foreach ($period as $day) {
+            if ($this->passes($day, $holidays)) {
+                $validDays->add($day);
+            }
+        }
+
+        return $validDays;
+    }
+
+    protected function passes(CarbonInterface $day, Collection $holidays): bool
+    {
+        if ($day->isWeekend()) {
+            return false;
+        }
+
+        if ($holidays->contains($day)) {
+            return false;
+        }
+
+        return true;
+    }
+}
diff --git a/app/Domain/Validation/Rules/ApprovedVacationDaysInSameRange.php b/app/Domain/Validation/Rules/ApprovedVacationDaysInSameRange.php
deleted file mode 100644
index eb39bf4..0000000
--- a/app/Domain/Validation/Rules/ApprovedVacationDaysInSameRange.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Toby\Domain\Validation\Rules;
-
-use Closure;
-use Toby\Eloquent\Models\VacationRequest;
-
-class ApprovedVacationDaysInSameRange implements VacationRequestRule
-{
-    public function check(VacationRequest $vacationRequest, Closure $next)
-    {
-        return $next($vacationRequest);
-    }
-}
diff --git a/app/Domain/Validation/Rules/DoesNotExceedLimitRule.php b/app/Domain/Validation/Rules/DoesNotExceedLimitRule.php
index 5c0d5eb..c9c4148 100644
--- a/app/Domain/Validation/Rules/DoesNotExceedLimitRule.php
+++ b/app/Domain/Validation/Rules/DoesNotExceedLimitRule.php
@@ -4,13 +4,23 @@ declare(strict_types=1);
 
 namespace Toby\Domain\Validation\Rules;
 
-use Closure;
+use Toby\Domain\VacationTypeConfigRetriever;
 use Toby\Eloquent\Models\VacationRequest;
 
 class DoesNotExceedLimitRule implements VacationRequestRule
 {
-    public function check(VacationRequest $vacationRequest, Closure $next)
+    public function __construct(
+        protected VacationTypeConfigRetriever $configRetriever,
+    ) {
+    }
+
+    public function check(VacationRequest $vacationRequest): bool
     {
-        return $next($vacationRequest);
+        return true;
+    }
+
+    public function errorMessage(): string
+    {
+        return __("You have exceeded your vacation limit.");
     }
 }
diff --git a/app/Domain/Validation/Rules/MinimumOneVacationDayRule.php b/app/Domain/Validation/Rules/MinimumOneVacationDayRule.php
index 63f9783..ef33dae 100644
--- a/app/Domain/Validation/Rules/MinimumOneVacationDayRule.php
+++ b/app/Domain/Validation/Rules/MinimumOneVacationDayRule.php
@@ -4,13 +4,25 @@ declare(strict_types=1);
 
 namespace Toby\Domain\Validation\Rules;
 
-use Closure;
+use Toby\Domain\VacationDaysCalculator;
 use Toby\Eloquent\Models\VacationRequest;
 
 class MinimumOneVacationDayRule implements VacationRequestRule
 {
-    public function check(VacationRequest $vacationRequest, Closure $next)
+    public function __construct(
+        protected VacationDaysCalculator $vacationDaysCalculator,
+    ) {
+    }
+
+    public function check(VacationRequest $vacationRequest): bool
     {
-        return $next($vacationRequest);
+        return $this->vacationDaysCalculator
+            ->calculateDays($vacationRequest->yearPeriod, $vacationRequest->from, $vacationRequest->to)
+            ->isNotEmpty();
+    }
+
+    public function errorMessage(): string
+    {
+        return __("Vacation needs minimum one day.");
     }
 }
diff --git a/app/Domain/Validation/Rules/NoApprovedVacationRequestsInRange.php b/app/Domain/Validation/Rules/NoApprovedVacationRequestsInRange.php
new file mode 100644
index 0000000..d06fd95
--- /dev/null
+++ b/app/Domain/Validation/Rules/NoApprovedVacationRequestsInRange.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Domain\Validation\Rules;
+
+use Toby\Domain\Enums\VacationRequestState;
+use Toby\Eloquent\Models\VacationRequest;
+
+class NoApprovedVacationRequestsInRange implements VacationRequestRule
+{
+    public function check(VacationRequest $vacationRequest): bool
+    {
+        return !$vacationRequest
+            ->user
+            ->vacationRequests()
+            ->overlapsWith($vacationRequest)
+            ->states(VacationRequestState::successStates())
+            ->exists();
+    }
+
+    public function errorMessage(): string
+    {
+        return __("You have approved vacation request in this range.");
+    }
+}
diff --git a/app/Domain/Validation/Rules/NoPendingVacationRequestInRange.php b/app/Domain/Validation/Rules/NoPendingVacationRequestInRange.php
new file mode 100644
index 0000000..3031b56
--- /dev/null
+++ b/app/Domain/Validation/Rules/NoPendingVacationRequestInRange.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Domain\Validation\Rules;
+
+use Toby\Domain\Enums\VacationRequestState;
+use Toby\Eloquent\Models\VacationRequest;
+
+class NoPendingVacationRequestInRange implements VacationRequestRule
+{
+    public function check(VacationRequest $vacationRequest): bool
+    {
+        return !$vacationRequest
+            ->user
+            ->vacationRequests()
+            ->overlapsWith($vacationRequest)
+            ->states(VacationRequestState::pendingStates())
+            ->exists();
+    }
+
+    public function errorMessage(): string
+    {
+        return __("You have pending vacation request in this range.");
+    }
+}
diff --git a/app/Domain/Validation/Rules/PendingVacationRequestInSameRange.php b/app/Domain/Validation/Rules/PendingVacationRequestInSameRange.php
deleted file mode 100644
index a0081b6..0000000
--- a/app/Domain/Validation/Rules/PendingVacationRequestInSameRange.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Toby\Domain\Validation\Rules;
-
-use Closure;
-use Toby\Eloquent\Models\VacationRequest;
-
-class PendingVacationRequestInSameRange implements VacationRequestRule
-{
-    public function check(VacationRequest $vacationRequest, Closure $next)
-    {
-        return $next($vacationRequest);
-    }
-}
diff --git a/app/Domain/Validation/Rules/UsedVacationDaysInSameRange.php b/app/Domain/Validation/Rules/UsedVacationDaysInSameRange.php
deleted file mode 100644
index 7d3b823..0000000
--- a/app/Domain/Validation/Rules/UsedVacationDaysInSameRange.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Toby\Domain\Validation\Rules;
-
-use Closure;
-use Toby\Eloquent\Models\VacationRequest;
-
-class UsedVacationDaysInSameRange
-{
-    public function check(VacationRequest $vacationRequest, Closure $next)
-    {
-        return $next($vacationRequest);
-    }
-}
diff --git a/app/Domain/Validation/Rules/VacationRangeIsInTheSameYearRule.php b/app/Domain/Validation/Rules/VacationRangeIsInTheSameYearRule.php
new file mode 100644
index 0000000..6c2faef
--- /dev/null
+++ b/app/Domain/Validation/Rules/VacationRangeIsInTheSameYearRule.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Domain\Validation\Rules;
+
+use Toby\Eloquent\Models\VacationRequest;
+
+class VacationRangeIsInTheSameYearRule implements VacationRequestRule
+{
+    public function check(VacationRequest $vacationRequest): bool
+    {
+        return $vacationRequest->from->isSameYear($vacationRequest->to);
+    }
+
+    public function errorMessage(): string
+    {
+        return __("The vacation request cannot be created at the turn of the year.");
+    }
+}
diff --git a/app/Domain/Validation/Rules/VacationRequestRule.php b/app/Domain/Validation/Rules/VacationRequestRule.php
index e50c92b..07af8d2 100644
--- a/app/Domain/Validation/Rules/VacationRequestRule.php
+++ b/app/Domain/Validation/Rules/VacationRequestRule.php
@@ -4,10 +4,10 @@ declare(strict_types=1);
 
 namespace Toby\Domain\Validation\Rules;
 
-use Closure;
 use Toby\Eloquent\Models\VacationRequest;
 
 interface VacationRequestRule
 {
-    public function check(VacationRequest $vacationRequest, Closure $next);
+    public function check(VacationRequest $vacationRequest): bool;
+    public function errorMessage(): string;
 }
diff --git a/app/Domain/Validation/VacationRequestValidator.php b/app/Domain/Validation/VacationRequestValidator.php
index f3cfa23..2bc39e6 100644
--- a/app/Domain/Validation/VacationRequestValidator.php
+++ b/app/Domain/Validation/VacationRequestValidator.php
@@ -4,32 +4,49 @@ declare(strict_types=1);
 
 namespace Toby\Domain\Validation;
 
-use Illuminate\Pipeline\Pipeline;
-use Toby\Domain\Validation\Rules\ApprovedVacationDaysInSameRange;
+use Illuminate\Contracts\Container\Container;
+use Illuminate\Validation\ValidationException;
 use Toby\Domain\Validation\Rules\DoesNotExceedLimitRule;
 use Toby\Domain\Validation\Rules\MinimumOneVacationDayRule;
-use Toby\Domain\Validation\Rules\PendingVacationRequestInSameRange;
+use Toby\Domain\Validation\Rules\NoApprovedVacationRequestsInRange;
+use Toby\Domain\Validation\Rules\NoPendingVacationRequestInRange;
+use Toby\Domain\Validation\Rules\VacationRangeIsInTheSameYearRule;
+use Toby\Domain\Validation\Rules\VacationRequestRule;
 use Toby\Eloquent\Models\VacationRequest;
 
 class VacationRequestValidator
 {
     protected array $rules = [
+        VacationRangeIsInTheSameYearRule::class,
         MinimumOneVacationDayRule::class,
         DoesNotExceedLimitRule::class,
-        PendingVacationRequestInSameRange::class,
-        ApprovedVacationDaysInSameRange::class,
+        NoPendingVacationRequestInRange::class,
+        NoApprovedVacationRequestsInRange::class,
     ];
 
     public function __construct(
-        protected Pipeline $pipeline,
+        protected Container $container,
     ) {
     }
 
+    /**
+     * @throws ValidationException
+     */
     public function validate(VacationRequest $vacationRequest): void
     {
-        $this->pipeline
-            ->send($vacationRequest)
-            ->through($this->rules)
-            ->via("check");
+        foreach ($this->rules as $rule) {
+            $rule = $this->makeRule($rule);
+
+            if (!$rule->check($vacationRequest)) {
+                throw ValidationException::withMessages([
+                    "vacationRequest" => $rule->errorMessage(),
+                ]);
+            }
+        }
+    }
+
+    protected function makeRule(string $class): VacationRequestRule
+    {
+        return $this->container->make($class);
     }
 }
diff --git a/app/Eloquent/Models/VacationRequest.php b/app/Eloquent/Models/VacationRequest.php
index 9c7ada0..0a81620 100644
--- a/app/Eloquent/Models/VacationRequest.php
+++ b/app/Eloquent/Models/VacationRequest.php
@@ -21,6 +21,7 @@ use Toby\Domain\Enums\VacationType;
  * @property VacationRequestState $state
  * @property Carbon $from
  * @property Carbon $to
+ * @property int $estimated_days
  * @property string $comment
  * @property User $user
  * @property YearPeriod $yearPeriod
@@ -68,6 +69,12 @@ class VacationRequest extends Model
         return $query->whereIn("state", $states);
     }
 
+    public function scopeOverlapsWith(Builder $query, self $vacationRequest): Builder
+    {
+        return $query->where("from", "<=", $vacationRequest->to)
+            ->where("to", ">=", $vacationRequest->from);
+    }
+
     protected static function newFactory(): VacationRequestFactory
     {
         return VacationRequestFactory::new();
diff --git a/app/Infrastructure/Http/Controllers/Api/CalculateVacationDaysController.php b/app/Infrastructure/Http/Controllers/Api/CalculateVacationDaysController.php
new file mode 100644
index 0000000..b8a8c33
--- /dev/null
+++ b/app/Infrastructure/Http/Controllers/Api/CalculateVacationDaysController.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Infrastructure\Http\Controllers\Api;
+
+use Illuminate\Http\JsonResponse;
+use Toby\Domain\VacationDaysCalculator;
+use Toby\Infrastructure\Http\Controllers\Controller;
+use Toby\Infrastructure\Http\Requests\Api\CalculateVacationDaysRequest;
+
+class CalculateVacationDaysController extends Controller
+{
+    public function __invoke(CalculateVacationDaysRequest $request, VacationDaysCalculator $calculator): JsonResponse
+    {
+        $days = $calculator->calculateDays($request->yearPeriod(), $request->from(), $request->to());
+
+        return new JsonResponse($days->all());
+    }
+}
diff --git a/app/Infrastructure/Http/Controllers/VacationRequestController.php b/app/Infrastructure/Http/Controllers/VacationRequestController.php
index 3c2eaf8..ca8be78 100644
--- a/app/Infrastructure/Http/Controllers/VacationRequestController.php
+++ b/app/Infrastructure/Http/Controllers/VacationRequestController.php
@@ -11,6 +11,7 @@ use Illuminate\Http\Response as LaravelResponse;
 use Inertia\Response;
 use Toby\Domain\Enums\VacationRequestState;
 use Toby\Domain\Enums\VacationType;
+use Toby\Domain\VacationDaysCalculator;
 use Toby\Domain\VacationRequestStateManager;
 use Toby\Domain\Validation\VacationRequestValidator;
 use Toby\Eloquent\Helpers\YearPeriodRetriever;
@@ -64,9 +65,15 @@ class VacationRequestController extends Controller
         VacationRequestRequest $request,
         VacationRequestValidator $vacationRequestValidator,
         VacationRequestStateManager $stateManager,
+        VacationDaysCalculator $vacationDaysCalculator,
     ): RedirectResponse {
         /** @var VacationRequest $vacationRequest */
         $vacationRequest = $request->user()->vacationRequests()->make($request->data());
+        $vacationRequest->estimated_days = $vacationDaysCalculator->calculateDays(
+            $vacationRequest->yearPeriod,
+            $vacationRequest->from,
+            $vacationRequest->to,
+        )->count();
 
         $vacationRequestValidator->validate($vacationRequest);
 
diff --git a/app/Infrastructure/Http/Requests/Api/CalculateVacationDaysRequest.php b/app/Infrastructure/Http/Requests/Api/CalculateVacationDaysRequest.php
new file mode 100644
index 0000000..72e37de
--- /dev/null
+++ b/app/Infrastructure/Http/Requests/Api/CalculateVacationDaysRequest.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Toby\Infrastructure\Http\Requests\Api;
+
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Support\Carbon;
+use Toby\Eloquent\Models\YearPeriod;
+use Toby\Infrastructure\Http\Rules\YearPeriodExists;
+
+class CalculateVacationDaysRequest extends FormRequest
+{
+    public function rules(): array
+    {
+        return [
+            "from" => ["required", "date_format:Y-m-d", new YearPeriodExists()],
+            "to" => ["required", "date_format:Y-m-d", new YearPeriodExists()],
+        ];
+    }
+
+    public function from(): Carbon
+    {
+        return Carbon::create($this->request->get("from"));
+    }
+
+    public function to(): Carbon
+    {
+        return Carbon::create($this->request->get("to"));
+    }
+
+    public function yearPeriod(): YearPeriod
+    {
+        return YearPeriod::findByYear(Carbon::create($this->request->get("from"))->year);
+    }
+}
diff --git a/app/Infrastructure/Http/Resources/VacationRequestResource.php b/app/Infrastructure/Http/Resources/VacationRequestResource.php
index 859dfea..009eeb6 100644
--- a/app/Infrastructure/Http/Resources/VacationRequestResource.php
+++ b/app/Infrastructure/Http/Resources/VacationRequestResource.php
@@ -20,6 +20,7 @@ class VacationRequestResource extends JsonResource
             "state" => $this->state->label(),
             "from" => $this->from->toDisplayString(),
             "to" => $this->to->toDisplayString(),
+            "estimatedDays" => $this->estimated_days,
             "comment" => $this->comment,
         ];
     }
diff --git a/config/cors.php b/config/cors.php
index c025685..34e1c4f 100644
--- a/config/cors.php
+++ b/config/cors.php
@@ -10,5 +10,5 @@ return [
     "allowed_headers" => ["*"],
     "exposed_headers" => [],
     "max_age" => 0,
-    "supports_credentials" => false,
+    "supports_credentials" => true,
 ];
diff --git a/database/factories/VacationRequestFactory.php b/database/factories/VacationRequestFactory.php
index e8bec48..3939367 100644
--- a/database/factories/VacationRequestFactory.php
+++ b/database/factories/VacationRequestFactory.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace Database\Factories;
 
 use Carbon\CarbonImmutable;
+use Carbon\CarbonPeriod;
 use Illuminate\Database\Eloquent\Factories\Factory;
 use Toby\Domain\Enums\VacationRequestState;
 use Toby\Domain\Enums\VacationType;
@@ -15,6 +16,7 @@ use Toby\Eloquent\Models\YearPeriod;
 class VacationRequestFactory extends Factory
 {
     protected $model = VacationRequest::class;
+    private static int $number = 1;
 
     public function definition(): array
     {
@@ -29,6 +31,7 @@ class VacationRequestFactory extends Factory
             "state" => $this->faker->randomElement(VacationRequestState::cases()),
             "from" => $from,
             "to" => $from->addDays($days),
+            "estimated_days" => fn(array $attributes) => $this->estimateDays($attributes),
             "comment" => $this->faker->boolean ? $this->faker->paragraph() : null,
         ];
     }
@@ -36,12 +39,15 @@ class VacationRequestFactory extends Factory
     protected function generateName(array $attributes): string
     {
         $year = YearPeriod::find($attributes["year_period_id"])->year;
-        $user = User::find($attributes["user_id"]);
-
-        $number = $user->vacationRequests()
-            ->whereYear("from", $year)
-            ->count() + 1;
+        $number = static::$number++;
 
         return "{$number}/{$year}";
     }
+
+    protected function estimateDays(array $attributes): int
+    {
+        $period = CarbonPeriod::create($attributes["from"], $attributes["to"]);
+
+        return $period->count();
+    }
 }
diff --git a/database/migrations/2022_01_26_100039_create_vacation_requests_table.php b/database/migrations/2022_01_26_100039_create_vacation_requests_table.php
index f5270da..b3f4e48 100644
--- a/database/migrations/2022_01_26_100039_create_vacation_requests_table.php
+++ b/database/migrations/2022_01_26_100039_create_vacation_requests_table.php
@@ -18,6 +18,7 @@ return new class() extends Migration {
             $table->foreignIdFor(YearPeriod::class)->constrained()->cascadeOnDelete();
             $table->string("type");
             $table->string("state")->nullable();
+            $table->integer("estimated_days");
             $table->date("from");
             $table->date("to");
             $table->text("comment")->nullable();
diff --git a/package-lock.json b/package-lock.json
index 64ebfd5..7795438 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,5 +1,5 @@
 {
-    "name": "application",
+    "name": "toby",
     "lockfileVersion": 2,
     "requires": true,
     "packages": {
@@ -15,6 +15,7 @@
                 "@tailwindcss/typography": "^0.5.0",
                 "@vue/compiler-sfc": "^3.2.26",
                 "autoprefixer": "^10.4.2",
+                "axios": "^0.25.0",
                 "echarts": "^5.2.2",
                 "flatpickr": "^4.6.9",
                 "laravel-mix": "^6.0.6",
@@ -1741,6 +1742,14 @@
                 "vue": "^3.0.0"
             }
         },
+        "node_modules/@inertiajs/inertia/node_modules/axios": {
+            "version": "0.21.4",
+            "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
+            "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+            "dependencies": {
+                "follow-redirects": "^1.14.0"
+            }
+        },
         "node_modules/@inertiajs/progress": {
             "version": "0.2.7",
             "resolved": "https://registry.npmjs.org/@inertiajs/progress/-/progress-0.2.7.tgz",
@@ -2642,11 +2651,11 @@
             }
         },
         "node_modules/axios": {
-            "version": "0.21.4",
-            "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
-            "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+            "version": "0.25.0",
+            "resolved": "https://registry.npmjs.org/axios/-/axios-0.25.0.tgz",
+            "integrity": "sha512-cD8FOb0tRH3uuEe6+evtAbgJtfxr7ly3fQjYcMcuPlgkwVS9xboaVIpcDV+cYQe+yGykgwZCs1pzjntcGa6l5g==",
             "dependencies": {
-                "follow-redirects": "^1.14.0"
+                "follow-redirects": "^1.14.7"
             }
         },
         "node_modules/babel-loader": {
@@ -10664,6 +10673,16 @@
                 "axios": "^0.21.1",
                 "deepmerge": "^4.0.0",
                 "qs": "^6.9.0"
+            },
+            "dependencies": {
+                "axios": {
+                    "version": "0.21.4",
+                    "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
+                    "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+                    "requires": {
+                        "follow-redirects": "^1.14.0"
+                    }
+                }
             }
         },
         "@inertiajs/inertia-vue3": {
@@ -11468,11 +11487,11 @@
             }
         },
         "axios": {
-            "version": "0.21.4",
-            "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
-            "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+            "version": "0.25.0",
+            "resolved": "https://registry.npmjs.org/axios/-/axios-0.25.0.tgz",
+            "integrity": "sha512-cD8FOb0tRH3uuEe6+evtAbgJtfxr7ly3fQjYcMcuPlgkwVS9xboaVIpcDV+cYQe+yGykgwZCs1pzjntcGa6l5g==",
             "requires": {
-                "follow-redirects": "^1.14.0"
+                "follow-redirects": "^1.14.7"
             }
         },
         "babel-loader": {
diff --git a/package.json b/package.json
index 6a0d9af..c69812f 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
         "@tailwindcss/typography": "^0.5.0",
         "@vue/compiler-sfc": "^3.2.26",
         "autoprefixer": "^10.4.2",
+        "axios": "^0.25.0",
         "echarts": "^5.2.2",
         "flatpickr": "^4.6.9",
         "laravel-mix": "^6.0.6",
diff --git a/resources/js/Pages/VacationRequest/Create.vue b/resources/js/Pages/VacationRequest/Create.vue
index 9333545..d2cef55 100644
--- a/resources/js/Pages/VacationRequest/Create.vue
+++ b/resources/js/Pages/VacationRequest/Create.vue
@@ -10,8 +10,26 @@
       class="border-t border-gray-200 px-6"
       @submit.prevent="createForm"
     >
+      <div
+        v-if="form.errors.vacationRequest"
+        class="rounded-md bg-red-50 p-4 mt-2"
+      >
+        <div class="flex">
+          <div class="flex-shrink-0">
+            <XCircleIcon class="h-5 w-5 text-red-400" />
+          </div>
+          <div class="ml-3">
+            <h3 class="text-sm font-medium text-red-800">
+              Wniosek nie mógł zostać utworzony
+            </h3>
+            <div class="mt-2 text-sm text-red-700">
+              <span>{{ form.errors.vacationRequest }}</span>
+            </div>
+          </div>
+        </div>
+      </div>
       <Listbox
-        v-model="form.vacationType"
+        v-model="form.type"
         as="div"
         class="sm:grid sm:grid-cols-3 py-4 items-center"
       >
@@ -21,9 +39,9 @@
         <div class="mt-1 relative sm:mt-0 sm:col-span-2">
           <ListboxButton
             class="bg-white relative w-full max-w-lg border rounded-md shadow-sm pl-3 pr-10 py-2 text-left cursor-default sm:text-sm focus:ring-1"
-            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.vacationType, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.vacationType }"
+            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.type, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.type }"
           >
-            <span class="block truncate">{{ form.vacationType.label }}</span>
+            <span class="block truncate">{{ form.type.label }}</span>
             <span class="absolute inset-y-0 right-0 flex items-center pr-2 pointer-events-none">
               <SelectorIcon class="h-5 w-5 text-gray-400" />
             </span>
@@ -38,15 +56,15 @@
               class="absolute z-10 mt-1 w-full max-w-lg bg-white shadow-lg max-h-60 rounded-md py-1 text-base ring-1 ring-black ring-opacity-5 overflow-auto focus:outline-none sm:text-sm"
             >
               <ListboxOption
-                v-for="vacationType in vacationTypes"
-                :key="vacationType.value"
+                v-for="type in vacationTypes"
+                :key="type.value"
                 v-slot="{ active, selected }"
                 as="template"
-                :value="vacationType"
+                :value="type"
               >
                 <li :class="[active ? 'text-white bg-blumilk-600' : 'text-gray-900', 'cursor-default select-none relative py-2 pl-3 pr-9']">
                   <span :class="[selected ? 'font-semibold' : 'font-normal', 'block truncate']">
-                    {{ vacationType.label }}
+                    {{ type.label }}
                   </span>
 
                   <span
@@ -60,10 +78,10 @@
             </ListboxOptions>
           </transition>
           <p
-            v-if="form.errors.vacationType"
+            v-if="form.errors.type"
             class="mt-2 text-sm text-red-600"
           >
-            {{ form.errors.vacationType }}
+            {{ form.errors.type }}
           </p>
         </div>
       </Listbox>
@@ -77,18 +95,18 @@
         <div class="mt-1 sm:mt-0 sm:col-span-2">
           <FlatPickr
             id="date_from"
-            v-model="form.dateFrom"
+            v-model="form.from"
             :config="fromInputConfig"
             placeholder="Wybierz datę"
             class="block w-full max-w-lg shadow-sm rounded-md sm:text-sm"
-            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.dateFrom, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.dateFrom }"
+            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.from, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.from }"
             @on-change="onFromChange"
           />
           <p
-            v-if="form.errors.dateFrom"
+            v-if="form.errors.from"
             class="mt-2 text-sm text-red-600"
           >
-            {{ form.errors.dateFrom }}
+            {{ form.errors.from }}
           </p>
         </div>
       </div>
@@ -102,25 +120,25 @@
         <div class="mt-1 sm:mt-0 sm:col-span-2">
           <FlatPickr
             id="date_to"
-            v-model="form.dateTo"
+            v-model="form.to"
             :config="toInputConfig"
             placeholder="Wybierz datę"
             class="block w-full max-w-lg shadow-sm rounded-md sm:text-sm"
-            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.dateTo, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.dateTo }"
+            :class="{ 'border-red-300 text-red-900 focus:outline-none focus:ring-red-500 focus:border-red-500': form.errors.to, 'focus:ring-blumilk-500 focus:border-blumilk-500 sm:text-sm border-gray-300': !form.errors.to }"
             @on-change="onToChange"
           />
           <p
-            v-if="form.errors.dateTo"
+            v-if="form.errors.to"
             class="mt-2 text-sm text-red-600"
           >
-            {{ form.errors.dateTo }}
+            {{ form.errors.to }}
           </p>
         </div>
       </div>
       <div class="sm:grid sm:grid-cols-3 py-4 items-center">
         <span class="block text-sm font-medium text-gray-700 sm:mt-px">Liczba dni urlopu</span>
         <div class="mt-1 sm:mt-0 sm:col-span-2 w-full max-w-lg bg-gray-50 border border-gray-300 rounded-md px-4 py-2 inline-flex items-center text-gray-500 sm:text-sm">
-          1
+          {{ estimatedDays.length }}
         </div>
       </div>
       <div class="sm:grid sm:grid-cols-3 py-4 items-center">
@@ -135,7 +153,7 @@
             id="comment"
             v-model="form.comment"
             rows="4"
-            class="shadow-sm focus:ring-indigo-500 focus:border-indigo-500 block w-full max-w-lg sm:text-sm border-gray-300 rounded-md"
+            class="shadow-sm focus:ring-blumilk-500 focus:border-blumilk-500 block w-full max-w-lg sm:text-sm border-gray-300 rounded-md"
           />
         </div>
       </div>
@@ -164,8 +182,9 @@
 import {useForm} from '@inertiajs/inertia-vue3'
 import FlatPickr from 'vue-flatpickr-component'
 import {Listbox, ListboxButton, ListboxLabel, ListboxOption, ListboxOptions} from '@headlessui/vue'
-import {CheckIcon, SelectorIcon} from '@heroicons/vue/solid'
-import {reactive} from 'vue'
+import {CheckIcon, SelectorIcon, XCircleIcon} from '@heroicons/vue/solid'
+import {reactive, ref} from 'vue'
+import axios from 'axios'
 
 export default {
   name: 'VacationRequestCreate',
@@ -178,6 +197,7 @@ export default {
     ListboxOptions,
     CheckIcon,
     SelectorIcon,
+    XCircleIcon,
   },
   props: {
     vacationTypes: {
@@ -191,12 +211,14 @@ export default {
   },
   setup(props) {
     const form = useForm({
-      dateFrom: null,
-      dateTo: null,
-      vacationType: props.vacationTypes[0],
+      from: null,
+      to: null,
+      type: props.vacationTypes[0],
       comment: null,
     })
 
+    const estimatedDays = ref([])
+
     const disableDates = [
       date => (date.getDay() === 0 || date.getDay() === 6),
     ]
@@ -213,6 +235,7 @@ export default {
 
     return {
       form,
+      estimatedDays,
       fromInputConfig,
       toInputConfig,
     }
@@ -221,18 +244,26 @@ export default {
     createForm() {
       this.form
         .transform(data => ({
-          from: data.dateFrom,
-          to: data.dateTo,
-          type: data.vacationType.value,
-          comment: data.comment,
+          ...data,
+          type: data.type.value,
         }))
         .post('/vacation-requests')
     },
     onFromChange(selectedDates, dateStr) {
       this.toInputConfig.minDate = dateStr
+
+      this.refreshEstimatedDays(this.form.from, this.form.to)
     },
     onToChange(selectedDates, dateStr) {
       this.fromInputConfig.maxDate = dateStr
+
+      this.refreshEstimatedDays(this.form.from, this.form.to)
+    },
+    refreshEstimatedDays(from, to) {
+      if (from && to) {
+        axios.post('/api/calculate-vacation-days', {from, to})
+          .then(res => this.estimatedDays = res.data)
+      }
     },
   },
 
diff --git a/resources/js/Pages/VacationRequest/Index.vue b/resources/js/Pages/VacationRequest/Index.vue
index 745f0d3..4530d0e 100644
--- a/resources/js/Pages/VacationRequest/Index.vue
+++ b/resources/js/Pages/VacationRequest/Index.vue
@@ -33,40 +33,40 @@
           <tr>
             <th
               scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+              class="px-4 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
             >
               Numer
             </th>
             <th
               scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+              class="px-4 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
             >
               Rodzaj urlopu
             </th>
             <th
               scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
-            >
-              Status
-            </th>
-            <th
-              scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+              class="px-4 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
             >
               Od
             </th>
             <th
               scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+              class="px-4 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
             >
               Do
             </th>
             <th
               scope="col"
-              class="px-6 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+              class="px-4 py-3 text-right text-xs font-semibold text-gray-500 uppercase tracking-wider"
             >
               Dni urlopu
             </th>
+            <th
+              scope="col"
+              class="px-4 py-3 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider"
+            >
+              Status
+            </th>
             <th scope="col" />
           </tr>
         </thead>
@@ -87,17 +87,17 @@
             <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
               {{ request.type }}
             </td>
-            <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
-              {{ request.state }}
-            </td>
             <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
               {{ request.from }}
             </td>
             <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
               {{ request.to }}
             </td>
+            <td class="px-4 py-4 whitespace-nowrap text-right text-sm text-gray-500">
+              {{ request.estimatedDays }}
+            </td>
             <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
-              X
+              {{ request.state }}
             </td>
             <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-500">
               <InertiaLink :href="`/vacation-requests/${request.id}`">
diff --git a/resources/js/Pages/VacationRequest/Show.vue b/resources/js/Pages/VacationRequest/Show.vue
index 6bee934..55a3f09 100644
--- a/resources/js/Pages/VacationRequest/Show.vue
+++ b/resources/js/Pages/VacationRequest/Show.vue
@@ -44,10 +44,10 @@
             </div>
             <div class="py-4 sm:py-5 sm:grid sm:grid-cols-3 sm:gap-4 sm:px-6">
               <dt class="text-sm font-medium text-gray-500">
-                Dni
+                Dni urlopu
               </dt>
               <dd class="mt-1 text-sm text-gray-900 sm:mt-0 sm:col-span-2">
-                x
+                {{ request.estimatedDays }}
               </dd>
             </div>
             <div class="py-4 sm:py-5 sm:grid sm:grid-cols-3 sm:gap-4 sm:px-6">
diff --git a/resources/lang/pl.json b/resources/lang/pl.json
index 29fae87..01cf187 100644
--- a/resources/lang/pl.json
+++ b/resources/lang/pl.json
@@ -16,8 +16,8 @@
   "sick_vacation": "Zwolnienie lekarskie",
   "employee": "Pracownik",
   "administrator": "Administrator",
-  "technical_approver": "Techniczny klepacz",
-  "administrative_approver": "Administracyjny klepacz",
+  "technical_approver": "Techniczny akceptujący",
+  "administrative_approver": "Administracyjny akceptujący",
   "created": "Utworzony",
   "canceled": "Anulowany",
   "rejected": "Odrzucony",
@@ -25,5 +25,10 @@
   "waiting_for_technical": "Czeka na akceptację od technicznego",
   "waiting_for_administrative": "Czeka na akceptację od administracyjnego",
   "accepted_by_technical": "Zaakceptowany przez technicznego",
-  "accepted_by_administrative": "Zaakceptowany przez administracyjnego"
+  "accepted_by_administrative": "Zaakceptowany przez administracyjnego",
+  "You have pending vacation request in this range.": "Masz oczekujący wniosek urlopowy w tym zakresie dat.",
+  "You have approved vacation request in this range.": "Masz zaakceptowany wniosek urlopowy w tym zakresie dat.",
+  "You have exceeded your vacation limit.": "Przekroczyłeś/aś limit urlopu.",
+  "Vacation needs minimum one day.": "Urlop musi być co najmniej na jeden dzień.",
+  "The vacation request cannot be created at the turn of the year.": "Wniosek urlopowy nie może zostać złożony na przełomie roku."
 }
diff --git a/resources/lang/pl/validation.php b/resources/lang/pl/validation.php
index 09fdc6d..733418d 100644
--- a/resources/lang/pl/validation.php
+++ b/resources/lang/pl/validation.php
@@ -114,4 +114,15 @@ return [
     "uploaded" => "Nie udało się wgrać pliku :attribute.",
     "url" => "Format pola :attribute jest nieprawidłowy.",
     "uuid" => "Pole :attribute musi być poprawnym identyfikatorem UUID.",
+    "attributes" => [
+        "to" => "do",
+        "from" => "od",
+        "firstName" => "imię",
+        "lastName" => "nazwisko",
+        "email" => "e-mail",
+        "position" => "stanowisko",
+        "employmentDate" => "data zatrudnienia",
+        "date" => "data",
+        "name" => "nazwa",
+    ],
 ];
diff --git a/resources/views/pdf/vacation-request.blade.php b/resources/views/pdf/vacation-request.blade.php
index 9f22109..9300bf2 100644
--- a/resources/views/pdf/vacation-request.blade.php
+++ b/resources/views/pdf/vacation-request.blade.php
@@ -74,7 +74,7 @@
         <h2>Wniosek o urlop</h2>
         <p class="content">
             Proszę o {{ mb_strtolower($vacationRequest->type->label()) }} w okresie od dnia {{ $vacationRequest->from->format("d.m.Y") }}
-            do dnia {{ $vacationRequest->to->format("d.m.Y") }} włącznie tj. x dni roboczych za rok {{ $vacationRequest->yearPeriod->year }}.
+            do dnia {{ $vacationRequest->to->format("d.m.Y") }} włącznie tj. {{ $vacationRequest->estimated_days }} dni roboczych za rok {{ $vacationRequest->yearPeriod->year }}.
         </p>
     </div>
 
diff --git a/routes/api.php b/routes/api.php
index 174d7fd..f418a99 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -1,3 +1,10 @@
 <?php
 
 declare(strict_types=1);
+
+use Illuminate\Support\Facades\Route;
+use Toby\Infrastructure\Http\Controllers\Api\CalculateVacationDaysController;
+
+Route::middleware("auth:sanctum")->group(function (): void {
+    Route::post("calculate-vacation-days", CalculateVacationDaysController::class);
+});