diff --git a/.rubocop.yml b/.rubocop.yml
index c2e973f0..9410af03 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -120,6 +120,10 @@ Metrics/ClassLength:
   Exclude:
     - 'app/models/conference.rb'
 
+Metrics/BlockLength:
+  Exclude:
+    - 'spec/models/conference_spec.rb'
+
 #################### Lint ###############################
 
 # Wrap your assignment in condition if you mean it, otherwise it is most likely equality check
diff --git a/app/controllers/admin/conferences_controller.rb b/app/controllers/admin/conferences_controller.rb
index 6aafe6c5..50360a64 100644
--- a/app/controllers/admin/conferences_controller.rb
+++ b/app/controllers/admin/conferences_controller.rb
@@ -82,7 +82,6 @@ module Admin
       short_title = @conference.short_title
       @conference.assign_attributes(conference_params)
       send_mail_on_conf_update = @conference.notify_on_dates_changed?
-      delete_event_schedules if @conference.start_hour_changed? || @conference.end_hour_changed?
 
       if @conference.update_attributes(conference_params)
         ConferenceDateUpdateMailJob.perform_later(@conference) if send_mail_on_conf_update
@@ -189,14 +188,5 @@ module Admin
                                          :targets, :targets_attributes,
                                          :campaigns, :campaigns_attributes, :registration_limit)
     end
-
-    def delete_event_schedules
-      event_schedules = EventSchedule.select do |e|
-        e.start_time.strftime('%H').to_i < @conference.start_hour ||
-        e.end_time.strftime('%H').to_i > @conference.end_hour ||
-        (e.end_time.strftime('%H').to_i == @conference.end_hour && e.end_time.strftime('%M').to_i > 0)
-      end
-      event_schedules.each(&:destroy)
-    end
   end
 end
diff --git a/app/models/conference.rb b/app/models/conference.rb
index f4d55d2e..224c1dfb 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -67,6 +67,7 @@ class Conference < ActiveRecord::Base
   before_create :create_email_settings
 
   after_create :create_free_ticket
+  after_update :delete_event_schedules
 
   ##
   # Checks if the user is registered to the conference
@@ -80,6 +81,20 @@ class Conference < ActiveRecord::Base
     user.present? && registrations.where(user_id: user.id).count > 0
   end
 
+  ##
+  # Delete all EventSchedules that are not in the hours range
+  # After the conference has been successfully updated
+  def delete_event_schedules
+    if start_hour_changed? || end_hour_changed?
+      event_schedules = program.event_schedules.select do |event_schedule|
+        event_schedule.start_time.hour < start_hour ||
+        event_schedule.end_time.hour > end_hour ||
+        (event_schedule.end_time.hour == end_hour && event_schedule.end_time.minute > 0)
+      end
+      event_schedules.each(&:destroy)
+    end
+  end
+
   ##
   # Checks if the registration for the conference is currently open
   #
diff --git a/app/models/program.rb b/app/models/program.rb
index ff0ab094..e8114f99 100644
--- a/app/models/program.rb
+++ b/app/models/program.rb
@@ -10,6 +10,7 @@ class Program < ActiveRecord::Base
   has_many :tracks, dependent: :destroy
   has_many :difficulty_levels, dependent: :destroy
   has_many :schedules, dependent: :destroy
+  has_many :event_schedules, through: :schedules
   belongs_to :selected_schedule, class_name: 'Schedule'
   has_many :events, dependent: :destroy do
     def require_registration
diff --git a/spec/models/conference_spec.rb b/spec/models/conference_spec.rb
index 47d64164..b5a6d5f0 100755
--- a/spec/models/conference_spec.rb
+++ b/spec/models/conference_spec.rb
@@ -1639,4 +1639,23 @@ describe Conference do
       expect(free_ticket.price_cents).to eq(0)
     end
   end
+
+  describe 'after_update' do
+    let(:conference) { create(:conference) }
+    let(:scheduled_event_before_conference) { create(:event_scheduled, program: conference.program, hour: conference.start_date + conference.start_hour.hours) }
+    let(:scheduled_event_after_conference) { create(:event_scheduled, program: conference.program, hour: conference.start_date + conference.end_hour.hours - 1.hour) }
+    let!(:scheduled_event_during_conference) { create(:event_scheduled, program: conference.program, hour: conference.start_date + conference.start_hour.hours + 3.hours) }
+
+    it 'delete event schedules that are not in hour ranges, when conference start hour is updated' do
+      scheduled_event_before_conference
+      conference.start_hour = conference.start_hour + 1
+      expect{ conference.save }.to change{ EventSchedule.count }.from(2).to(1)
+    end
+
+    it 'delete event schedules that are not in hour ranges, when conference end hour is updated' do
+      scheduled_event_after_conference
+      conference.end_hour = conference.end_hour - 2
+      expect{ conference.save }.to change{ EventSchedule.count }.from(2).to(1)
+    end
+  end
 end