diff --git a/modules/meeting/app/contracts/meetings/update_contract.rb b/modules/meeting/app/contracts/meetings/update_contract.rb
index 090eb4b0fa61..9bb44d583a08 100644
--- a/modules/meeting/app/contracts/meetings/update_contract.rb
+++ b/modules/meeting/app/contracts/meetings/update_contract.rb
@@ -28,7 +28,10 @@
 
 module Meetings
   class UpdateContract < BaseContract
+    include Redmine::I18n
+
     validate :user_allowed_to_edit
+    validate :not_before_scheduled_time
 
     attribute :lock_version do
       if model.lock_version.nil? || model.lock_version_changed?
@@ -41,5 +44,15 @@ def user_allowed_to_edit
         errors.add :base, :error_unauthorized
       end
     end
+
+    def not_before_scheduled_time
+      return unless model.recurring_meeting_id && model.scheduled_meeting
+      return unless model.changed.intersect?(%w[start_time start_date])
+
+      scheduled_time = model.scheduled_meeting.start_time
+      if model.start_time < scheduled_time
+        errors.add :start_date, :after, date: format_date(scheduled_time)
+      end
+    end
   end
 end
diff --git a/modules/meeting/spec/services/meetings/update_service_integration_spec.rb b/modules/meeting/spec/services/meetings/update_service_integration_spec.rb
new file mode 100644
index 000000000000..697629cfaf50
--- /dev/null
+++ b/modules/meeting/spec/services/meetings/update_service_integration_spec.rb
@@ -0,0 +1,67 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "spec_helper"
+
+RSpec.describe Meetings::UpdateService, "integration", type: :model do
+  include Redmine::I18n
+
+  shared_let(:project) { create(:project, enabled_module_names: %i[meetings]) }
+  shared_let(:user) do
+    create(:user, member_with_permissions: { project => %i(view_meetings edit_meetings) })
+  end
+
+  let(:instance) { described_class.new(model: meeting, user:) }
+  let(:attributes) { {} }
+  let(:params) { {} }
+
+  let(:service_result) { instance.call(attributes:, **params) }
+  let(:updated_meeting) { service_result.result }
+
+  context "when meeting is in a series and scheduled to the future" do
+    let!(:recurring_meeting) { create(:recurring_meeting, project:, frequency: "daily") }
+    let!(:meeting) { create(:structured_meeting, recurring_meeting:, project:, start_time: Time.zone.tomorrow + 10.hours) }
+    let!(:schedule) do
+      create(:scheduled_meeting,
+             meeting:,
+             start_time: Time.zone.today + 10.hours,
+             recurring_meeting:)
+    end
+
+    context "when trying to move it to before the scheduled time" do
+      let(:params) do
+        { start_time: Time.zone.yesterday + 10.hours }
+      end
+
+      it "does not be valid" do
+        expect(service_result).not_to be_success
+        expect(service_result.errors[:start_date]).to include("must be after #{format_date(Time.zone.today + 10.hours)}.")
+      end
+    end
+  end
+end