diff --git a/app/models/conference.rb b/app/models/conference.rb
index 5bfdd282..f21742a1 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -179,7 +179,7 @@ class Conference < ActiveRecord::Base
     result = []
 
     if call_for_papers && events
-      submissions = events.group("strftime('%W', created_at)").count
+      submissions = events.group(:week).count
       start_week = call_for_papers.start_week
       weeks = call_for_papers.weeks
       result = calculate_items_per_week(start_week, weeks, submissions)
@@ -196,7 +196,7 @@ class Conference < ActiveRecord::Base
     result = []
 
     if call_for_papers && events
-      submissions = events.where('state = ?', state).group("strftime('%W', created_at)").count
+      submissions = events.where('state = ?', state).group(:week).count
       start_week = call_for_papers.start_week
       weeks = call_for_papers.weeks
       result = calculate_items_per_week(start_week, weeks, submissions)
@@ -216,7 +216,7 @@ class Conference < ActiveRecord::Base
         registration_start_date &&
         registration_end_date
 
-      reg = registrations.group("strftime('%W', created_at)").count
+      reg = registrations.group(:week).count
       start_week = get_registration_start_week
       weeks = registration_weeks
       result = calculate_items_per_week(start_week, weeks, reg)
diff --git a/app/models/event.rb b/app/models/event.rb
index 47c611fc..d5a37501 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -5,6 +5,8 @@ class Event < ActiveRecord::Base
 
   acts_as_commentable
 
+  after_create :set_week
+
   has_many :event_people, :dependent => :destroy
   has_many :event_attachments, :dependent => :destroy
   has_many :people, :through => :event_people
@@ -203,4 +205,8 @@ class Event < ActiveRecord::Base
     self.guid = guid
   end
 
+  def set_week
+    self.week = created_at.strftime('%W')
+    save!
+  end
 end
diff --git a/app/models/registration.rb b/app/models/registration.rb
index e218eb8f..f9e663d7 100644
--- a/app/models/registration.rb
+++ b/app/models/registration.rb
@@ -34,7 +34,16 @@ class Registration < ActiveRecord::Base
   
   alias_attribute :other_needs, :other_special_needs
 
+  after_create :set_week
+
   def week
     created_at.strftime('%W').to_i
   end
+
+  private
+
+  def set_week
+    self.week = created_at.strftime('%W')
+    save!
+  end
 end
diff --git a/db/migrate/20140625112608_add_week_to_event.rb b/db/migrate/20140625112608_add_week_to_event.rb
new file mode 100644
index 00000000..72d05389
--- /dev/null
+++ b/db/migrate/20140625112608_add_week_to_event.rb
@@ -0,0 +1,17 @@
+class AddWeekToEvent < ActiveRecord::Migration
+  class Event < ActiveRecord::Base
+  end
+
+  def up
+    add_column :events, :week, :integer
+    Event.reset_column_information
+    Event.find_each do |event|
+      event.week = event.created_at.strftime('%W')
+      event.save!
+    end
+  end
+
+  def down
+    remove_column :events, :week
+  end
+end
diff --git a/db/migrate/20140625114813_add_week_to_registration.rb b/db/migrate/20140625114813_add_week_to_registration.rb
new file mode 100644
index 00000000..29484a79
--- /dev/null
+++ b/db/migrate/20140625114813_add_week_to_registration.rb
@@ -0,0 +1,17 @@
+class AddWeekToRegistration < ActiveRecord::Migration
+  class Registration < ActiveRecord::Base
+  end
+
+  def up
+    add_column :registrations, :week, :integer
+    Registration.reset_column_information
+    Registration.find_each do |registration|
+      registration.week = registration.created_at.strftime('%W')
+      registration.save!
+    end
+  end
+
+  def down
+    remove_column :registrations, :week
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 563673c2..a9294f6d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140623101032) do
+ActiveRecord::Schema.define(version: 20140625114813) do
 
   create_table "ahoy_events", force: true do |t|
     t.uuid     "visit_id"
@@ -224,6 +224,7 @@ ActiveRecord::Schema.define(version: 20140623101032) do
     t.string   "media_type"
     t.boolean  "require_registration"
     t.integer  "difficulty_level_id"
+    t.integer  "week"
   end
 
   create_table "events_registrations", id: false, force: true do |t|
@@ -328,6 +329,7 @@ ActiveRecord::Schema.define(version: 20140623101032) do
     t.text     "other_special_needs"
     t.boolean  "attended",                    default: false
     t.boolean  "volunteer"
+    t.integer  "week"
   end
 
   create_table "registrations_social_events", id: false, force: true do |t|