diff --git a/lib/redmine/helpers/gantt.rb b/lib/redmine/helpers/gantt.rb
index 285eb66a0..e4663e08e 100644
--- a/lib/redmine/helpers/gantt.rb
+++ b/lib/redmine/helpers/gantt.rb
@@ -623,7 +623,7 @@ module Redmine
       def coordinates(start_date, end_date, progress, zoom=nil)
         zoom ||= @zoom
         coords = {}
-        if start_date && end_date && start_date < self.date_to && end_date > self.date_from
+        if start_date && end_date && start_date <= self.date_to && end_date >= self.date_from
           if start_date > self.date_from
             coords[:start] = start_date - self.date_from
             coords[:bar_start] = start_date - self.date_from
diff --git a/test/unit/lib/redmine/helpers/gantt_test.rb b/test/unit/lib/redmine/helpers/gantt_test.rb
index 3e45735ef..c98c35710 100644
--- a/test/unit/lib/redmine/helpers/gantt_test.rb
+++ b/test/unit/lib/redmine/helpers/gantt_test.rb
@@ -44,6 +44,12 @@ class Redmine::Helpers::GanttHelperTest < Redmine::HelperTest
   def gantt_start
     @gantt.date_from
   end
+  private :gantt_start
+
+  def gantt_end
+    @gantt.date_to
+  end
+  private :gantt_end
 
   # Creates a Gantt chart for a 4 week span
   def create_gantt(project=Project.generate!, options={})
@@ -354,6 +360,26 @@ class Redmine::Helpers::GanttHelperTest < Redmine::HelperTest
     assert_select 'div.task_todo[style*="left:28px"]', 1
   end
 
+  test "#line todo line should end on the leftmost date in the gantt" do
+    create_gantt
+    [gantt_start - 1, gantt_start].each do |start_date|
+      @output_buffer = @gantt.line(start_date, gantt_start, 30, false, 'line', :format => :html, :zoom => 4)
+      # the leftmost date (Date.today - 14 days)
+      assert_select 'div.task_todo[style*="left:0px"]', 1, @output_buffer
+      assert_select 'div.task_todo[style*="width:2px"]', 1, @output_buffer
+    end
+  end
+
+  test "#line todo line should start on the rightmost date in the gantt" do
+    create_gantt
+    [gantt_end, gantt_end + 1].each do |end_date|
+      @output_buffer = @gantt.line(gantt_end, end_date, 30, false, 'line', :format => :html, :zoom => 4)
+      # the rightmost date (Date.today + 14 days)
+      assert_select 'div.task_todo[style*="left:112px"]', 1, @output_buffer
+      assert_select 'div.task_todo[style*="width:2px"]', 1, @output_buffer
+    end
+  end
+
   test "#line todo line should be the total width" do
     create_gantt
     @output_buffer = @gantt.line(today - 7, today + 7, 30, false, 'line', :format => :html, :zoom => 4)