diff --git a/.rubocop.yml b/.rubocop.yml
index 497d45e8..6500f653 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -95,7 +95,9 @@ Metrics/BlockNesting:
   Max: 4
 
 Metrics/ClassLength:
-  Max: 575
+  Max: 300
+  Exclude: 
+    - 'app/models/conference.rb'
 
 # avoid redundunt curly braces when it is obvious that hash is used
 Style/BracesAroundHashParameters:
diff --git a/app/controllers/admin/conferences_controller.rb b/app/controllers/admin/conferences_controller.rb
index b7063e6e..84f92838 100644
--- a/app/controllers/admin/conferences_controller.rb
+++ b/app/controllers/admin/conferences_controller.rb
@@ -82,6 +82,7 @@ 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
@@ -177,7 +178,8 @@ module Admin
 
     def conference_params
       params.require(:conference).permit(:title, :short_title, :description, :timezone,
-                                         :start_date, :end_date, :rooms_attributes, :tracks_attributes,
+                                         :start_date, :end_date, :start_hour, :end_hour,
+                                         :rooms_attributes, :tracks_attributes,
                                          :tickets_attributes, :event_types_attributes,
                                          :picture, :picture_cache, :questions_attributes,
                                          :question_ids, :answers_attributes, :answer_ids, :difficulty_levels_attributes,
@@ -187,5 +189,14 @@ 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/controllers/schedules_controller.rb b/app/controllers/schedules_controller.rb
index 91559aa1..0b135328 100644
--- a/app/controllers/schedules_controller.rb
+++ b/app/controllers/schedules_controller.rb
@@ -14,16 +14,15 @@ class SchedulesController < ApplicationController
     @events_xml = schedules.map(&:event).group_by{ |event| event.time.to_date } if schedules
     @dates = @conference.start_date..@conference.end_date
     @step_minutes = EventType::LENGTH_STEP.minutes
-    @conf_start = 9
-    conf_end = 20
-    @conf_period = conf_end - @conf_start
+    @conf_start = @conference.start_hour
+    @conf_period = @conference.end_hour - @conf_start
 
     # the schedule takes you to today if it is a date of the schedule
     @current_day = @conference.current_conference_day
     @day = @current_day.present? ? @current_day : @dates.first
     return unless @current_day
     # the schedule takes you to the current time if it is beetween the start and the end time.
-    @hour_column = @conference.hours_from_start_time(@conf_start, conf_end)
+    @hour_column = @conference.hours_from_start_time(@conf_start, @conference.end_hour)
   end
 
   def events
diff --git a/app/models/conference.rb b/app/models/conference.rb
index a54f4e22..b5e01a09 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -1,6 +1,3 @@
-# rubocop:disable Metrics/ClassLength
-##
-# This class represents a conference
 class Conference < ActiveRecord::Base
   require 'uri'
   serialize :events_per_week, Hash
@@ -54,7 +51,9 @@ class Conference < ActiveRecord::Base
   validates_presence_of :title,
                         :short_title,
                         :start_date,
-                        :end_date
+                        :end_date,
+                        :start_hour,
+                        :end_hour
 
   validates_uniqueness_of :short_title
   validates_format_of :short_title, with: /\A[a-zA-Z0-9_-]*\z/
@@ -62,6 +61,7 @@ class Conference < ActiveRecord::Base
 
   # This validation is needed since a conference with a start date greater than the end date is not possible
   validate :valid_date_range?
+  validate :valid_times_range?
   before_create :generate_guid
   before_create :add_color
   before_create :create_email_settings
@@ -678,6 +678,19 @@ class Conference < ActiveRecord::Base
     errors.add(:start_date, 'Start date is greater than End date') if start_date && end_date && start_date > end_date
   end
 
+  ##
+  # Checks if start hour of the conference is greater or equal than the end hour
+  # and that both hours are beetween 0 and 24
+  #
+  # Reports an error when such a condition is found
+  def valid_times_range?
+    if start_hour && end_hour
+      errors.add(:start_hour, 'is lower than 0') if start_hour < 0
+      errors.add(:end_hour, 'is lower or equal than start hour') if end_hour <= start_hour
+      errors.add(:end_hour, 'is greater than 24') if end_hour > 24
+    end
+  end
+
   ##
   # Calculates the weeks from a start and a end week.
   #
@@ -1065,4 +1078,3 @@ class Conference < ActiveRecord::Base
     result
   end
 end
-# rubocop:enable Metrics/ClassLength
diff --git a/app/views/admin/conferences/edit.html.haml b/app/views/admin/conferences/edit.html.haml
index dfc6d72a..8ba8f80e 100644
--- a/app/views/admin/conferences/edit.html.haml
+++ b/app/views/admin/conferences/edit.html.haml
@@ -21,6 +21,8 @@
         = f.input :timezone, :as => :time_zone, :hint => "The conference time zone"
         = f.input :start_date, :as => :string, :input_html => { :id => "conference-start-datepicker", :readonly => "readonly"  }
         = f.input :end_date, :as => :string, :input_html => { :id => "conference-end-datepicker", :readonly => "readonly"  }
+        = f.input :start_hour, :input_html => {size: 2, type: 'number', min: 0, max: 23}
+        = f.input :end_hour, :input_html => {size: 2, type: 'number', min: 1, max: 24}
       = f.inputs name: "Registrations" do
         = f.input :registration_limit, as: :number, in: 0..9999, hint: "Limit the number of registrations to the conference (0 no limit)"
       = f.action :submit, :as => :button, :button_html => {:class => "btn btn-primary"}
diff --git a/app/views/admin/schedules/_day_tab.html.haml b/app/views/admin/schedules/_day_tab.html.haml
index 57be4999..61f6e862 100644
--- a/app/views/admin/schedules/_day_tab.html.haml
+++ b/app/views/admin/schedules/_day_tab.html.haml
@@ -9,7 +9,7 @@
       .room-name
         - room_date_event_schedules = date_event_schedules.select{ |e| e.room == room }
         = room.name
-      - (9*cells_per_hour..18*cells_per_hour).each do |slot|
+      - (@conference.start_hour * cells_per_hour..@conference.end_hour * cells_per_hour).each do |slot|
         - hour = slot / cells_per_hour
         - minutes = (EventType::LENGTH_STEP * (slot % cells_per_hour)).to_s.rjust(2, '0')
         - time = "#{hour}:#{minutes}"
diff --git a/db/migrate/20160815094215_add_times_to_conferences.rb b/db/migrate/20160815094215_add_times_to_conferences.rb
new file mode 100644
index 00000000..758ed841
--- /dev/null
+++ b/db/migrate/20160815094215_add_times_to_conferences.rb
@@ -0,0 +1,6 @@
+class AddTimesToConferences < ActiveRecord::Migration
+  def change
+    add_column :conferences, :start_hour, :integer, default: 9
+    add_column :conferences, :end_hour, :integer, default: 20
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index d0d4de72..34c30a04 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -98,6 +98,8 @@ ActiveRecord::Schema.define(version: 20170213145807) do
     t.text     "description"
     t.integer  "registration_limit", default: 0
     t.string   "picture"
+    t.integer  "start_hour",         default: 9
+    t.integer  "end_hour",           default: 20
   end
 
   create_table "conferences_questions", id: false, force: :cascade do |t|
diff --git a/spec/factories/conferences.rb b/spec/factories/conferences.rb
index d92a7e88..8a9186a6 100644
--- a/spec/factories/conferences.rb
+++ b/spec/factories/conferences.rb
@@ -7,6 +7,8 @@ FactoryGirl.define do
     timezone { Faker::Address.time_zone }
     start_date { Date.today }
     end_date { 6.days.from_now }
+    start_hour 9
+    end_hour 20
     registration_limit 0
     description { Faker::Hipster.paragraph }
 
diff --git a/spec/models/conference_spec.rb b/spec/models/conference_spec.rb
index 8520a978..aa824319 100755
--- a/spec/models/conference_spec.rb
+++ b/spec/models/conference_spec.rb
@@ -1545,6 +1545,14 @@ describe Conference do
       should validate_presence_of(:end_date)
     end
 
+    it 'is not valid without a start date' do
+      should validate_presence_of(:start_hour)
+    end
+
+    it 'is not valid without an end date' do
+      should validate_presence_of(:end_hour)
+    end
+
     it 'is not valid with a duplicate short title' do
       should validate_uniqueness_of(:short_title)
     end
@@ -1572,6 +1580,21 @@ describe Conference do
       end
     end
 
+    describe 'valid_times_range?' do
+
+      it 'is not valid if start hour is lower than 0' do
+        expect(subject.start_hour).to be >= 0
+      end
+
+      it 'is not valid if end hour is lower or equal than start hour' do
+        expect(subject.start_hour).to be < subject.end_hour
+      end
+
+      it 'is not valid if end hour is greater than 24' do
+        expect(subject.end_hour).to be <= 24
+      end
+    end
+
     describe 'before create callbacks' do
 
       it 'has an email setting after creation' do