diff --git a/app/models/rate.rb b/app/models/rate.rb
index 36cff18..58beebd 100644
--- a/app/models/rate.rb
+++ b/app/models/rate.rb
@@ -82,6 +82,19 @@ class Rate < ActiveRecord::Base
     end
     store_cache_timestamp('last_caching_run', Time.now.to_s)
   end
+
+  def self.update_all_time_entries_to_refresh_cache
+    Lockfile('refresh_cache', :retries => 0) do
+      TimeEntry.find_each do |time_entry| # batch find
+        begin
+          time_entry.save_cached_cost
+        rescue Rate::InvalidParameterException => ex
+          puts "Error saving #{time_entry.id}: #{ex.message}"
+        end
+      end
+    end
+    store_cache_timestamp('last_cache_clearing_run', Time.now.to_s)
+  end
   
   private
   def self.for_user_project_and_date(user, project, date)
diff --git a/lib/tasks/cache.rake b/lib/tasks/cache.rake
index e60cf15..f8710ff 100644
--- a/lib/tasks/cache.rake
+++ b/lib/tasks/cache.rake
@@ -1,8 +1,13 @@
 namespace :rate_plugin do
   namespace :cache do
-    desc "Update Time Entry cost caches"
+    desc "Update Time Entry cost caches for Time Entries without a cost"
     task :update_cost_cache => :environment do
       Rate.update_all_time_entries_with_missing_cost
     end
+
+    desc "Clear and update all Time Entry cost caches"
+    task :refresh_cost_cache => :environment do
+      Rate.update_all_time_entries_to_refresh_cache
+    end
   end
 end
diff --git a/test/unit/rate_test.rb b/test/unit/rate_test.rb
index e492771..99a585e 100644
--- a/test/unit/rate_test.rb
+++ b/test/unit/rate_test.rb
@@ -301,4 +301,33 @@ class RateTest < ActiveSupport::TestCase
       assert Time.parse(Setting.plugin_redmine_rate['last_caching_run']), "Last run timestamp not parseable"
     end
   end
+
+  context "#update_all_time_entries_to_refresh_cache" do
+    setup do
+      @user = User.generate!
+      @project = Project.generate!
+      @date = Date.today.to_s
+      @rate = Rate.generate!(:user => @user, :project => @project, :date_in_effect => @date, :amount => 200.0)
+      @time_entry1 = TimeEntry.generate!({:user => @user, :project => @project, :spent_on => @date, :hours => 10.0, :activity => TimeEntryActivity.generate!})
+      @time_entry2 = TimeEntry.generate!({:user => @user, :project => @project, :spent_on => @date, :hours => 20.0, :activity => TimeEntryActivity.generate!})
+    end
+    
+    should "update the caches of all Time Entries" do
+      assert_equal "0", ActiveRecord::Base.connection.select_all('select count(*) as count from time_entries where cost IS NULL').first["count"]
+
+      Rate.update_all_time_entries_to_refresh_cache
+
+      assert_equal "0", ActiveRecord::Base.connection.select_all('select count(*) as count from time_entries where cost IS NULL').first["count"]
+
+    end
+    
+    should "timestamp a successful run" do
+      assert_equal nil, Setting.plugin_redmine_rate['last_cache_clearing_run']
+
+      Rate.update_all_time_entries_to_refresh_cache
+
+      assert Setting.plugin_redmine_rate['last_cache_clearing_run'], "Last run not timestamped"
+      assert Time.parse(Setting.plugin_redmine_rate['last_cache_clearing_run']), "Last run timestamp not parseable"
+    end
+  end
 end