diff --git a/frontend/src/app/features/work-packages/components/wp-table/timeline/container/wp-timeline-container.directive.ts b/frontend/src/app/features/work-packages/components/wp-table/timeline/container/wp-timeline-container.directive.ts
index 5f45d86233..6028c2bfe6 100644
--- a/frontend/src/app/features/work-packages/components/wp-table/timeline/container/wp-timeline-container.directive.ts
+++ b/frontend/src/app/features/work-packages/components/wp-table/timeline/container/wp-timeline-container.directive.ts
@@ -150,7 +150,7 @@ export class WorkPackageTimelineTableController extends UntilDestroyedMixin impl
     const scrollBar = document.querySelector('.work-packages-tabletimeline--timeline-side');
     if (scrollBar) {
       scrollBar.addEventListener('scroll', () => {
-       this.requireNonWorkingDays(this.getFirstDayInViewport().format('YYYY-MM-DD'), this.getLastDayInViewport().format('YYYY-MM-DD'));
+        this.requireNonWorkingDays(this.getFirstDayInViewport().format('YYYY-MM-DD'), this.getLastDayInViewport().format('YYYY-MM-DD'));
       });
     }
 
diff --git a/spec/features/work_packages/timeline/timeline_dates_spec.rb b/spec/features/work_packages/timeline/timeline_dates_spec.rb
index fe475ec2b8..255d8ed3fb 100644
--- a/spec/features/work_packages/timeline/timeline_dates_spec.rb
+++ b/spec/features/work_packages/timeline/timeline_dates_spec.rb
@@ -125,14 +125,18 @@ RSpec.describe 'Work package timeline date formatting',
       let(:current_user) { create :admin, language: 'en' }
 
       shared_let(:week_days) { week_with_saturday_and_sunday_as_weekend }
+      shared_let(:non_working_day) do
+        create(:non_working_day,
+               date: '28-12-2020')
+      end
 
       it 'shows them as disabled' do
         expect_date_week work_package.start_date.iso8601, '01'
 
         expect(page).to have_selector('[data-qa-selector="wp-timeline--non-working-day_27-12-2020"]')
         expect(page).to have_selector('[data-qa-selector="wp-timeline--non-working-day_2-1-2021"]')
+        expect(page).to have_selector('[data-qa-selector="wp-timeline--non-working-day_28-12-2020"]')
 
-        expect(page).to have_no_selector('[data-qa-selector="wp-timeline--non-working-day_28-12-2020"]')
         expect(page).to have_no_selector('[data-qa-selector="wp-timeline--non-working-day_29-12-2020"]')
         expect(page).to have_no_selector('[data-qa-selector="wp-timeline--non-working-day_30-12-2020"]')
         expect(page).to have_no_selector('[data-qa-selector="wp-timeline--non-working-day_31-12-2020"]')