diff --git a/config/packages/kimai.yaml b/config/packages/kimai.yaml
index 5bb10129..273f2f20 100644
--- a/config/packages/kimai.yaml
+++ b/config/packages/kimai.yaml
@@ -124,6 +124,7 @@ kimai:
 #        week_numbers: true
 #        weekends: true
 #        day_limit: 4
+#        slot_duration: '00:30:00'
 #        businessHours:
 #            days: [1, 2, 3, 4, 5]
 #            begin: '08:00'
diff --git a/src/Configuration/CalendarConfiguration.php b/src/Configuration/CalendarConfiguration.php
index c7019a4b..205ddcf6 100644
--- a/src/Configuration/CalendarConfiguration.php
+++ b/src/Configuration/CalendarConfiguration.php
@@ -97,4 +97,9 @@ class CalendarConfiguration implements SystemBundleConfiguration
     {
         return $this->find('google.sources');
     }
+
+    public function getSlotDuration(): string
+    {
+        return (string) $this->find('slot_duration');
+    }
 }
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 16c300c9..2f68045d 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -250,6 +250,7 @@ class Configuration implements ConfigurationInterface
             ->children()
                 ->booleanNode('week_numbers')->defaultTrue()->end()
                 ->integerNode('day_limit')->defaultValue(4)->end()
+                ->scalarNode('slot_duration')->defaultValue('00:30:00')->end()
                 ->arrayNode('businessHours')
                     ->addDefaultsIfNotSet()
                     ->children()
diff --git a/templates/calendar/user.html.twig b/templates/calendar/user.html.twig
index ca7cd281..0c33f93d 100644
--- a/templates/calendar/user.html.twig
+++ b/templates/calendar/user.html.twig
@@ -215,9 +215,8 @@
                 eventResize: changeHandler,
                 {% endif %}
             {% endif %}
-                /*
-                slotDuration: '00:30:00',                               // TODO make me configurable
-                */
+                slotDuration: '{{ config.slotDuration }}',
+                slotLabelInterval: '{{ config.slotDuration }}',
                 minTime: '{{ config.timeframeBegin }}',
                 maxTime: '{{ config.timeframeEnd }}',
                 defaultTimedEventDuration: '00:30'
diff --git a/tests/Configuration/CalendarConfigurationTest.php b/tests/Configuration/CalendarConfigurationTest.php
index 6ce70279..2363140f 100644
--- a/tests/Configuration/CalendarConfigurationTest.php
+++ b/tests/Configuration/CalendarConfigurationTest.php
@@ -42,6 +42,7 @@ class CalendarConfigurationTest extends TestCase
                 'end' => '19:27'
             ],
             'day_limit' => 20,
+            'slot_duration' => '01:11:00',
             'week_numbers' => false,
             'google' => [
                 'api_key' => 'wertwertwegsdfbdf243w567fg8ihuon',
@@ -72,6 +73,7 @@ class CalendarConfigurationTest extends TestCase
         $this->assertEquals([2, 4, 6], $sut->getBusinessDays());
         $this->assertEquals('07:49', $sut->getBusinessTimeBegin());
         $this->assertEquals('19:27', $sut->getBusinessTimeEnd());
+        $this->assertEquals('01:11:00', $sut->getSlotDuration());
         $this->assertEquals(20, $sut->getDayLimit());
         $this->assertFalse($sut->isShowWeekNumbers());
 
diff --git a/tests/Controller/CalendarControllerTest.php b/tests/Controller/CalendarControllerTest.php
index 20d4eae9..a087131c 100644
--- a/tests/Controller/CalendarControllerTest.php
+++ b/tests/Controller/CalendarControllerTest.php
@@ -68,6 +68,7 @@ class CalendarControllerTest extends ControllerBaseTest
             ],
             'day_limit' => 20,
             'week_numbers' => false,
+            'slot_duration' => '00:15:00',
             'google' => [
                 'api_key' => 'wertwertwegsdfbdf243w567fg8ihuon',
                 'sources' => [
diff --git a/tests/DependencyInjection/AppExtensionTest.php b/tests/DependencyInjection/AppExtensionTest.php
index 99f9b029..38c2ecf5 100644
--- a/tests/DependencyInjection/AppExtensionTest.php
+++ b/tests/DependencyInjection/AppExtensionTest.php
@@ -63,6 +63,7 @@ class AppExtensionTest extends TestCase
             'kimai.calendar' => [
                 'week_numbers' => true,
                 'day_limit' => 4,
+                'slot_duration' => '00:30:00',
                 'businessHours' => [
                     'days' => [1, 2, 3, 4, 5],
                     'begin' => '08:00',