diff --git a/app/models/task.rb b/app/models/task.rb
index 8d17652c..453af12b 100644
--- a/app/models/task.rb
+++ b/app/models/task.rb
@@ -108,7 +108,7 @@ class Task < ActiveRecord::Base
   end
 
   def exclude_from_periodic_task_group
-    if changed? and not new_record?
+    if changed? and not new_record? and not changed.include? 'periodic_task_group_id'
       self.periodic_task_group = nil
     end
   end
diff --git a/db/migrate/20121115073715_create_periodic_task_groups.rb b/db/migrate/20130615073715_create_periodic_task_groups.rb
similarity index 100%
rename from db/migrate/20121115073715_create_periodic_task_groups.rb
rename to db/migrate/20130615073715_create_periodic_task_groups.rb
diff --git a/db/migrate/20130622095040_move_weekly_tasks.rb b/db/migrate/20130622095040_move_weekly_tasks.rb
new file mode 100644
index 00000000..7c9cde8f
--- /dev/null
+++ b/db/migrate/20130622095040_move_weekly_tasks.rb
@@ -0,0 +1,60 @@
+class MoveWeeklyTasks < ActiveRecord::Migration
+  def up
+    Workgroup.where(weekly_task: true).each do |workgroup|
+      task_group = PeriodicTaskGroup.create
+      puts "Moving weekly task for workgroup #{workgroup.name} to group #{task_group.id}"
+      workgroup.tasks.undone.each do |task|
+        task_group.tasks << task if weekly_task?(workgroup, task)
+      end
+      tasks = task_group.tasks.order(:due_date)
+      task_group.next_task_date = tasks.last.due_date + PeriodicTaskGroup::PeriodDays unless tasks.empty?
+      task_group.save!
+      puts "Associated #{tasks.count} tasks with group and set next_task_date to #{task_group.next_task_date}"
+    end
+  end
+
+  def down
+    PeriodicTaskGroup.all.each do |task_group|
+      unless task_group.tasks.empty?
+        task = task_group.tasks.first
+        workgroup = task.workgroup
+        puts "Writing task data of group #{task_group.id} to workgroup #{workgroup.name}"
+        workgroup_attributes = {
+          weekly_task: true,
+          weekday: task.due_date.days_to_week_start(:sunday),
+          task_name: task.name,
+          task_description: task.description,
+          task_required_users: task.required_users,
+          task_duration: task.duration
+        }
+        workgroup.update_attributes workgroup_attributes
+        task_group.tasks.update_all weekly: true
+      end
+    end
+  end
+
+private
+  def weekly_task?(workgroup, task)
+    group_task = {
+      weekday: workgroup.weekday,
+      name: workgroup.task_name,
+      description: workgroup.task_description,
+      required_users: workgroup.task_required_users,
+      duration: workgroup.task_duration,
+      weekly: true,
+      done: false,
+      workgroup_id: workgroup.id
+    }
+    task_task = {
+      weekday: task.due_date.days_to_week_start(:sunday),
+      name: task.name,
+      description: task.description,
+      required_users: task.required_users,
+      duration: task.duration,
+      weekly: task.weekly,
+      done: task.done,
+      workgroup_id: task.workgroup_id
+    }
+    group_task == task_task
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 59fa21c4..73cb2ef1 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20121230142516) do
+ActiveRecord::Schema.define(:version => 20130622095040) do
 
   create_table "article_categories", :force => true do |t|
     t.string "name",        :default => "", :null => false