diff --git a/app/Helper/MWTimestampHelper.php b/app/Helper/MWTimestampHelper.php
index a5d03f71e..bab92e404 100644
--- a/app/Helper/MWTimestampHelper.php
+++ b/app/Helper/MWTimestampHelper.php
@@ -15,8 +15,13 @@ class MWTimestampHelper {
     private const MWTimestampFormat = 'YmdHis';
 
     public static function getCarbonFromMWTimestamp(string $MWTimestamp): CarbonImmutable {
-        $carbon = CarbonImmutable::createFromFormat(self::MWTimestampFormat, $MWTimestamp);
-        if ($carbon === null) {
+        try {
+            $carbon = CarbonImmutable::createFromFormat(self::MWTimestampFormat, $MWTimestamp);
+        } catch (InvalidFormatException $exception) {
+            throw new InvalidFormatException('Unable to create Carbon object', 0, $exception);
+        }
+
+        if (!$carbon instanceof CarbonImmutable) {
             throw new InvalidFormatException('Unable to create Carbon object');
         }
 
diff --git a/tests/Helper/MWTimestampHelperTest.php b/tests/Helper/MWTimestampHelperTest.php
index ed054cdb4..a82d81f9d 100644
--- a/tests/Helper/MWTimestampHelperTest.php
+++ b/tests/Helper/MWTimestampHelperTest.php
@@ -19,6 +19,7 @@ public function testGetCarbonFromMWTimestamp() {
 
     public function testGetCarbonFromMWTimestampWithInvalidTimestamp() {
         $this->expectException(InvalidFormatException::class);
+        $this->expectExceptionMessage('Unable to create Carbon object');
 
         $invalidMwTimestamp = 'invalid_timestamp';
         MWTimestampHelper::getCarbonFromMWTimestamp($invalidMwTimestamp);
diff --git a/tests/Jobs/PlatformStatsSummaryJobTest.php b/tests/Jobs/PlatformStatsSummaryJobTest.php
index 4a954200f..d94e970dc 100644
--- a/tests/Jobs/PlatformStatsSummaryJobTest.php
+++ b/tests/Jobs/PlatformStatsSummaryJobTest.php
@@ -274,4 +274,50 @@ public function testCreationStats() {
         );
 
     }
+
+    public function testPrepareStatsTreatsSecondPrecisionTimestampAtThresholdAsActive() {
+        $currentTime = CarbonImmutable::now();
+
+        $wiki = Wiki::factory()->create(['deleted_at' => null, 'domain' => 'thresholdtest.com']);
+        WikiDb::create([
+            'name' => 'mwdb_threshold_' . $wiki->id,
+            'user' => 'user',
+            'password' => 'password',
+            'version' => 'version',
+            'prefix' => 'prefix',
+            'wiki_id' => $wiki->id,
+        ]);
+
+        Http::fake([
+            $this->mwBackendHost . '/w/api.php?action=query&list=allpages&apnamespace=122&apcontinue=&aplimit=max&format=json' => Http::response([
+                'query' => ['allpages' => []],
+            ], 200),
+            $this->mwBackendHost . '/w/api.php?action=query&list=allpages&apnamespace=120&apcontinue=&aplimit=max&format=json' => Http::response([
+                'query' => ['allpages' => []],
+            ], 200),
+        ]);
+
+        $job = new PlatformStatsSummaryJob;
+        (function ($resolver): void {
+            $this->mwHostResolver = $resolver;
+        })->call($job, $this->mockMwHostResolver);
+
+        $groups = $job->prepareStats([
+            [
+                'wiki' => 'thresholdtest.com',
+                'edits' => 1,
+                'pages' => 1,
+                'users' => 1,
+                'active_users' => 1,
+                'lastEdit' => MWTimestampHelper::getMWTimestampFromCarbon(
+                    $currentTime->subSeconds(config('wbstack.platform_summary_inactive_threshold'))
+                ),
+                'first100UsingOauth' => '0',
+                'platform_summary_version' => 'v1',
+            ],
+        ], [$wiki]);
+
+        $this->assertSame(1, $groups['edited_last_90_days']);
+        $this->assertSame(0, $groups['not_edited_last_90_days']);
+    }
 }
diff --git a/tests/Jobs/SendEmptyWikiNotificationsJobTest.php b/tests/Jobs/SendEmptyWikiNotificationsJobTest.php
index 7fb09ba36..dd07b544c 100644
--- a/tests/Jobs/SendEmptyWikiNotificationsJobTest.php
+++ b/tests/Jobs/SendEmptyWikiNotificationsJobTest.php
@@ -38,7 +38,7 @@ public function testEmptyWikiNotificationsSendNotification() {
         Notification::fake();
         $user = User::factory()->create(['verified' => true]);
         $wiki = Wiki::factory()->create(['created_at' => $thresholdDaysAgo]);
-        $manager = WikiManager::factory()->create(['wiki_id' => $wiki->id, 'user_id' => $user->id]);
+        WikiManager::factory()->create(['wiki_id' => $wiki->id, 'user_id' => $user->id]);
         $wiki->wikiLifecycleEvents()->updateOrCreate(['first_edited' => null]);
 
         $job = new SendEmptyWikiNotificationsJob;
@@ -50,6 +50,24 @@ public function testEmptyWikiNotificationsSendNotification() {
         );
     }
 
+    // empty wikis, that are almost old enough (29 days and 23 hrs)
+    public function testEmptyWikiNotificationsNotSendNotification() {
+        $thresholdDaysAgo = Carbon::now()
+            ->subDays((config('wbstack.wiki_empty_notification_threshold') - 1))
+            ->subHours(23)
+            ->toDateTimeString();
+
+        Notification::fake();
+        $user = User::factory()->create(['verified' => true]);
+        $wiki = Wiki::factory()->create(['created_at' => $thresholdDaysAgo]);
+        WikiManager::factory()->create(['wiki_id' => $wiki->id, 'user_id' => $user->id]);
+        $wiki->wikiLifecycleEvents()->updateOrCreate(['first_edited' => null]);
+
+        $job = new SendEmptyWikiNotificationsJob;
+        $this->assertFalse($job->checkIfWikiIsOldAndEmpty($wiki));
+        $job->handle();
+    }
+
     // fresh wiki that does not have lifecycle event records yet
     public function testEmptyWikiNotificationsFreshWiki() {
         $now = Carbon::now()->toDateTimeString();
diff --git a/tests/Routes/Wiki/ConversionMetricTest.php b/tests/Routes/Wiki/ConversionMetricTest.php
index a1c479401..07f031821 100644
--- a/tests/Routes/Wiki/ConversionMetricTest.php
+++ b/tests/Routes/Wiki/ConversionMetricTest.php
@@ -58,10 +58,10 @@ private function createTestWiki($name, $createdWeeksAgo, $firstEditedWeeksAgo, $
         $wiki->created_at = $current_date->subWeeks($createdWeeksAgo);
         $events = $wiki->wikiLifecycleEvents();
         $update = [];
-        if ($lastEditedWeeksAgo) {
+        if ($lastEditedWeeksAgo !== null) {
             $update['last_edited'] = $current_date->subWeeks($lastEditedWeeksAgo);
         }
-        if ($firstEditedWeeksAgo) {
+        if ($firstEditedWeeksAgo !== null) {
             $update['first_edited'] = $current_date->subWeeks($firstEditedWeeksAgo);
         }
         $events->updateOrCreate($update);
@@ -134,6 +134,39 @@ public function testDownloadJson() {
         );
     }
 
+    public function testDownloadJsonTruncatesFractionalDayDiffs() {
+        $currentDate = CarbonImmutable::now();
+        $createdAt = $currentDate->subDays(200)->subHours(12); // 200.5 days ago
+        $firstEditedAt = $createdAt->addDays(1)->addHours(12); // 1.5 days after
+        $lastEditedAt = $currentDate->subDays(100); // 100 days ago
+
+        $wiki = Wiki::factory()->create([
+            'domain' => 'fractional.days.cloud',
+            'sitename' => 'Fractional Days Site',
+        ]);
+        WikiSiteStats::factory()->create([
+            'wiki_id' => $wiki->id,
+            'pages' => 77,
+            'activeusers' => 2,
+        ]);
+        $wiki->created_at = $createdAt;
+        $wiki->wikiLifecycleEvents()->updateOrCreate([
+            'first_edited' => $firstEditedAt,
+            'last_edited' => $lastEditedAt,
+        ]);
+        $wiki->save();
+
+        $response = $this->getJson($this->route);
+
+        $response->assertStatus(200);
+        $response->assertJsonFragment([
+            'domain' => 'fractional.days.cloud',
+            'time_to_engage_days' => 1,
+            'time_before_wiki_abandoned_days' => 100,
+            'number_of_active_editors' => 2,
+        ]);
+    }
+
     public function testFunctionalWithMissingLifecycleEventsandStats() {
         $wiki = Wiki::factory()->create([
             'domain' => 'very.new.wikibase.cloud', 'sitename' => 'bsite',