diff --git a/app/Service/DashboardService.php b/app/Service/DashboardService.php
index 869b53d0..7bb58687 100644
--- a/app/Service/DashboardService.php
+++ b/app/Service/DashboardService.php
@@ -47,18 +47,21 @@ class DashboardService
     {
         $result = [];
         $windowSize = 24 / $windows;
+        $end = Carbon::now($timeZone)->endOfDay()->subHours(3)->utc()->toDateTimeString();
+        $start = Carbon::now($timeZone)->subDays($days)->startOfDay()->utc()->toDateTimeString();
+
         $date = Carbon::now($timeZone)->startOfDay();
-        $end = $date->copy()->endOfDay()->utc()->toDateTimeString();
-        $start = $end;
         for ($i = 0; $i < $days; $i++) {
+            $dateString = $date->format('Y-m-d');
             $tempDate = $date->copy();
-            $start = $tempDate->utc()->toDateTimeString();
+            $start = $tempDate->copy()->utc()->toDateTimeString();
             $tempWindows = [];
             for ($j = 0; $j < $windows; $j++) {
-                $tempWindow = $tempDate->addHours($windowSize)->utc()->toDateTimeString();
+                $tempWindow = $tempDate->utc()->toDateTimeString();
                 $tempWindows[] = $tempWindow;
+                $tempDate->addHours($windowSize);
             }
-            $result[$date->format('Y-m-d')] = $tempWindows;
+            $result[$dateString] = $tempWindows;
             $date->subDay();
         }
 
@@ -420,14 +423,14 @@ class DashboardService
             SELECT time_ranges.start, EXTRACT(epoch FROM sum(LEAST(time_ranges."end", coalesce(time_entries."end", :now::timestamp)) - GREATEST(time_ranges.start, time_entries.start))) AS aggregate
             FROM  (
                SELECT time_range_starts.start AS start, time_range_starts.start + interval \'3 hours\' AS "end"
-               FROM generate_series(:start_time_ranges::timestamp, :end_time_ranges::timestamp, interval \'3 hours\') as time_range_starts (start)
+               FROM generate_series(:start_time_ranges::timestamp, :end_time_ranges::timestamp + interval \'3 hours\', interval \'3 hours\') as time_range_starts (start)
             ) time_ranges
             JOIN   time_entries ON time_entries.start < time_ranges."end"
-                      AND coalesce(time_entries."end", :now::timestamp)   > time_ranges.start
-            where time_entries.user_id = :user_id and
+                      AND coalesce(time_entries."end", :now::timestamp) > time_ranges.start
+            WHERE time_entries.user_id = :user_id and
                   time_entries.organization_id = :organization_id
-            GROUP  BY time_ranges.start
-            ORDER  BY time_ranges.start
+            GROUP BY time_ranges.start
+            ORDER BY time_ranges.start
         ', [
             'start_time_ranges' => $lastDaysSplitInWindows['start'],
             'end_time_ranges' => $lastDaysSplitInWindows['end'],
diff --git a/tests/Unit/Service/DashboardServiceTest.php b/tests/Unit/Service/DashboardServiceTest.php
index 69b0cd97..9212b77e 100644
--- a/tests/Unit/Service/DashboardServiceTest.php
+++ b/tests/Unit/Service/DashboardServiceTest.php
@@ -536,18 +536,18 @@ class DashboardServiceTest extends TestCase
     public function test_last_seven_days_returns_spend_time_in_the_last_seven_days_aggregated_in_three_hour_blocks(): void
     {
         // Arrange
-        $now = Carbon::create(2024, 4, 17, 12, 0, 0, 'Europe/Vienna');
+        $now = Carbon::create(2024, 4, 17, 12, 0, 0, 'Europe/Vienna')->utc();
         $this->travelTo($now);
         $organization = Organization::factory()->create();
         $user = User::factory()->create([
             'timezone' => 'Europe/Vienna',
         ]);
         $timeEntryOverWholePeriod = TimeEntry::factory()->forUser($user)->forOrganization($organization)->create([
-            'start' => now('Europe/Vienna')->subDays(7)->startOfDay()->subMinute()->utc(),
-            'end' => now('Europe/Vienna')->endOfDay()->addMinute()->utc(), // TODO: addMinute should not be necessary
+            'start' => now('Europe/Vienna')->subDays(7)->startOfDay()->utc(),
+            'end' => now('Europe/Vienna')->endOfDay()->addSecond()->utc(), // TODO: fix problem with last second
         ]);
         $timeEntryOverWholePeriodWithoutEnd = TimeEntry::factory()->forUser($user)->forOrganization($organization)->create([
-            'start' => now('Europe/Vienna')->subDays(7)->startOfDay()->subMinute()->utc(),
+            'start' => now('Europe/Vienna')->subDays(7)->startOfDay()->utc(),
             'end' => null,
         ]);
         $timeEntry1Task1 = TimeEntry::factory()->forUser($user)->forOrganization($organization)->create([
@@ -562,16 +562,16 @@ class DashboardServiceTest extends TestCase
         $this->assertSame([
             0 => [
                 'date' => '2024-04-17',
-                'duration' => 115800,
+                'duration' => 130200,
                 'history' => [
                     0 => 21600,
                     1 => 21600,
-                    2 => 22200,
-                    3 => 18000,
+                    2 => 21600,
+                    3 => 22200,
                     4 => 10800,
                     5 => 10800,
-                    6 => 10800, // TODO
-                    7 => 0, // TODO
+                    6 => 10800,
+                    7 => 10800,
                 ],
             ],
             1 => [