diff --git a/app/controllers/admin/conference_controller.rb b/app/controllers/admin/conference_controller.rb
index ac175e14..d34ee1ed 100644
--- a/app/controllers/admin/conference_controller.rb
+++ b/app/controllers/admin/conference_controller.rb
@@ -21,11 +21,11 @@ class Admin::ConferenceController < ApplicationController
     @conferences.each do |c|
       # Event submissions over time chart
       @submissions[c.short_title] = c.get_submissions_per_week
-      @cfp_weeks.push(c.cfp_weeks)
+      @cfp_weeks.push(@submissions[c.short_title].length)
 
       # Conference registrations over time chart
       @registrations[c.short_title] = c.get_registrations_per_week
-      @registration_weeks.push(c.registration_weeks)
+      @registration_weeks.push(@registrations[c.short_title].length)
     end
 
     @cfp_weeks = @cfp_weeks.max
diff --git a/app/models/conference.rb b/app/models/conference.rb
index c86c4df8..cdbd26fd 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -270,14 +270,16 @@ class Conference < ActiveRecord::Base
   def calculate_items_per_week(start_week, weeks, items)
     sum = 0
     result = []
-    last_key = start_week + 1
+    last_key = start_week - 1
 
-    items.each_with_index do |(key, value), index|
-      # Padding left
-      if index == 0
-        result = Array.new(key.to_i - start_week, 0)
-      # Padding middle
-      elsif last_key < (key.to_i - 1)
+    if !items.empty? && start_week > items.keys[0].to_i
+      start_week = items.keys[0].to_i
+      weeks += start_week - items.keys[0].to_i + 1
+    end
+
+    items.each do |key, value|
+      # Padding
+      if last_key < (key.to_i - 1)
         result += Array.new(key.to_i - last_key - 1, sum)
       end
 
diff --git a/spec/models/conference_spec.rb b/spec/models/conference_spec.rb
index 7f49addd..2f947160 100644
--- a/spec/models/conference_spec.rb
+++ b/spec/models/conference_spec.rb
@@ -70,6 +70,24 @@ describe Conference do
 
   describe '#get_submissions_per_week' do
 
+    it 'does calculate correct if cfp start date is altered' do
+      cfp = create(:call_for_papers)
+      cfp.start_date = Date.new(2014, 05, 26)
+      cfp.end_date = Date.new(2014, 05, 26) + 21
+      subject.call_for_papers = cfp
+      subject.events += [create(:event, created_at: Date.new(2014, 05, 26) - 7)]
+      expect(subject.get_submissions_per_week).to eq([1, 1, 1, 1, 1])
+    end
+
+    it 'does calculate correct if cfp end date is altered' do
+      cfp = create(:call_for_papers)
+      cfp.start_date = Date.new(2014, 05, 26)
+      cfp.end_date = Date.new(2014, 05, 26) + 21
+      subject.call_for_papers = cfp
+      subject.events += [create(:event, created_at: Date.new(2014, 05, 26) + 28)]
+      expect(subject.get_submissions_per_week).to eq([0, 0, 0, 0, 1])
+    end
+
     it 'pads with zeros if there are no submissions' do
       cfp = create(:call_for_papers)
       cfp.start_date = Date.new(2014, 05, 26)