fix: round up trial duration to avoid Carbon float truncation

app/Models/PolydockAppInstance.php

@@ -1110,8 +1110,9 @@ public function calculateAndSetTrialDates(?int $overrideDurationDays = null, ?bo
      */
     public function calculateAndSetTrialDatesFromEndDate($trialEndDateTime, bool $saveModel = false): self
     {
-        // Calculate days between now and end date
-        $durationDays = now()->diffInDays($trialEndDateTime);
+        // diffInDays() returns a float in Carbon 3; round up so a partial day still
+        // grants a full trial day rather than being truncated toward zero.
+        $durationDays = (int) ceil((float) now()->diffInDays($trialEndDateTime));
 
         return $this->calculateAndSetTrialDates($durationDays, $saveModel);
     }

tests/Unit/Models/TrialDateCalculationTest.php

@@ -0,0 +1,124 @@
+<?php
+
+namespace Tests\Unit\Models;
+
+use App\Events\PolydockAppInstanceCreatedWithNewStatus;
+use App\Events\PolydockAppInstanceStatusChanged;
+use App\Models\PolydockAppInstance;
+use App\Models\PolydockStore;
+use App\Models\PolydockStoreApp;
+use App\Models\UserGroup;
+use App\Polydock\Apps\Generic\PolydockAiApp;
+use App\Polydock\Core\Enums\PolydockAppInstanceStatus;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Carbon;
+use Illuminate\Support\Facades\Event;
+use Tests\TestCase;
+
+class TrialDateCalculationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private PolydockStoreApp $storeApp;
+
+    private UserGroup $group;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $store = PolydockStore::factory()->create();
+        $this->storeApp = PolydockStoreApp::factory()->create([
+            'polydock_store_id' => $store->id,
+            'trial_duration_days' => 7,
+            'send_midtrial_email' => true,
+            'send_one_day_left_email' => true,
+            'send_trial_complete_email' => true,
+        ]);
+        $this->group = UserGroup::factory()->create();
+
+        Event::fake([
+            PolydockAppInstanceCreatedWithNewStatus::class,
+            PolydockAppInstanceStatusChanged::class,
+        ]);
+    }
+
+    protected function tearDown(): void
+    {
+        Carbon::setTestNow();
+
+        parent::tearDown();
+    }
+
+    private function makeInstance(): PolydockAppInstance
+    {
+        $instance = new PolydockAppInstance;
+        $instance->polydock_store_app_id = $this->storeApp->id;
+        $instance->user_group_id = $this->group->id;
+        $instance->name = 'trial-date-test';
+        $instance->app_type = PolydockAiApp::class;
+        $instance->status = PolydockAppInstanceStatus::NEW;
+        $instance->save();
+
+        return $instance;
+    }
+
+    public function test_whole_days_in_future_sets_trial_ends_at_exactly_that_many_days_out(): void
+    {
+        Carbon::setTestNow('2026-07-01 12:00:00');
+
+        $instance = $this->makeInstance();
+        $endDate = now()->copy()->addDays(5); // exactly 5 whole days
+
+        $instance->calculateAndSetTrialDatesFromEndDate($endDate);
+
+        $this->assertNotNull($instance->trial_ends_at);
+        $this->assertSame(
+            now()->copy()->addDays(5)->toDateTimeString(),
+            $instance->trial_ends_at->toDateTimeString()
+        );
+    }
+
+    public function test_partial_day_rounds_up_so_trial_is_not_short_changed(): void
+    {
+        // Regression: Carbon 3 diffInDays() returns a float (e.g. 5.5); truncation
+        // toward zero would leave the trial ~1 day short of the requested end.
+        Carbon::setTestNow('2026-07-01 12:00:00');
+
+        $instance = $this->makeInstance();
+        $endDate = now()->copy()->addDays(5)->addHours(13); // 5 days + 13h => rounds up to 6
+
+        $instance->calculateAndSetTrialDatesFromEndDate($endDate);
+
+        $this->assertNotNull($instance->trial_ends_at);
+        // Rounds up to 6 whole days rather than truncating to 5.
+        $this->assertSame(
+            now()->copy()->addDays(6)->toDateTimeString(),
+            $instance->trial_ends_at->toDateTimeString()
+        );
+        // And the trial never ends before the requested end date.
+        $this->assertTrue(
+            $instance->trial_ends_at->greaterThanOrEqualTo($endDate),
+            'trial_ends_at should be on or after the requested end date'
+        );
+    }
+
+    public function test_end_date_in_the_past_leaves_trial_ends_at_null(): void
+    {
+        Carbon::setTestNow('2026-07-01 12:00:00');
+
+        $instance = $this->makeInstance();
+
+        // Prime a valid trial first so the assertion actually exercises the
+        // null-reset path rather than passing on a fresh instance's null.
+        $instance->calculateAndSetTrialDates(7);
+        $this->assertNotNull($instance->trial_ends_at);
+
+        $endDate = now()->copy()->subDays(3); // in the past
+
+        $instance->calculateAndSetTrialDatesFromEndDate($endDate);
+
+        // Guard ($durationDays > 0) means no negative trial is set.
+        $this->assertNull($instance->trial_ends_at);
+    }
+}