Index: lib/redmine/helpers/calendar.rb
===================================================================
--- lib/redmine/helpers/calendar.rb	(revision 4175)
+++ lib/redmine/helpers/calendar.rb	(working copy)
@@ -48,8 +48,8 @@
       # Sets calendar events
       def events=(events)
         @events = events
-        @ending_events_by_days = @events.group_by {|event| event.due_date}
-        @starting_events_by_days = @events.group_by {|event| event.start_date}
+        @ending_events_by_days = @events.group_by {|event| event.due_date ? event.due_date.to_date() : nil}
+        @starting_events_by_days = @events.group_by {|event| event.start_date ? event.start_date.to_date() : nil}
       end
       
       # Returns events for the given day
Index: lib/redmine/helpers/gantt.rb
===================================================================
--- lib/redmine/helpers/gantt.rb	(revision 4175)
+++ lib/redmine/helpers/gantt.rb	(working copy)
@@ -292,14 +292,14 @@
           case options[:format]
           when :html
             output = ''
-            i_left = ((project.start_date - self.date_from)*options[:zoom]).floor
+            i_left = ((project.start_date.to_date - self.date_from)*options[:zoom]).floor
 
-            start_date = project.start_date
+            start_date = project.start_date.to_date
             start_date ||= self.date_from
             start_left = ((start_date - self.date_from)*options[:zoom]).floor
 
-            i_end_date = ((project.due_date <= self.date_to) ? project.due_date : self.date_to )
-            i_done_date = start_date + ((project.due_date - start_date+1)* project.completed_percent(:include_subprojects => true)/100).floor
+            i_end_date = ((project.due_date.to_date <= self.date_to) ? project.due_date.to_date : self.date_to )
+            i_done_date = start_date + ((project.due_date.to_date - start_date+1)* project.completed_percent(:include_subprojects => true)/100).floor
             i_done_date = (i_done_date <= self.date_from ? self.date_from : i_done_date )
             i_done_date = (i_done_date >= self.date_to ? self.date_to : i_done_date )
             
@@ -353,7 +353,7 @@
             output
           when :image
             options[:image].stroke('transparent')
-            i_left = options[:subject_width] + ((project.due_date - self.date_from)*options[:zoom]).floor
+            i_left = options[:subject_width] + ((project.due_date.to_date - self.date_from)*options[:zoom]).floor
 
             # Make sure negative i_left doesn't overflow the subject
             if i_left > options[:subject_width]
@@ -364,7 +364,7 @@
             end
           when :pdf
             options[:pdf].SetY(options[:top]+1.5)
-            i_left = ((project.due_date - @date_from)*options[:zoom])
+            i_left = ((project.due_date.to_date - @date_from)*options[:zoom])
 
             # Make sure negative i_left doesn't overflow the subject
             if i_left > 0
@@ -426,14 +426,15 @@
           case options[:format]
           when :html
             output = ''
-            i_left = ((version.start_date - self.date_from)*options[:zoom]).floor
+            i_left = ((version.start_date.to_date - self.date_from)*options[:zoom]).floor
             # TODO: or version.fixed_issues.collect(&:start_date).min
             start_date = version.fixed_issues.minimum('start_date') if version.fixed_issues.present?
             start_date ||= self.date_from
+			start_date = start_date.to_date
             start_left = ((start_date - self.date_from)*options[:zoom]).floor
 
-            i_end_date = ((version.due_date <= self.date_to) ? version.due_date : self.date_to )
-            i_done_date = start_date + ((version.due_date - start_date+1)* version.completed_pourcent/100).floor
+            i_end_date = ((version.due_date.to_date <= self.date_to) ? version.due_date.to_date : self.date_to )
+            i_done_date = start_date + ((version.due_date.to_date - start_date+1)* version.completed_pourcent/100).floor
             i_done_date = (i_done_date <= self.date_from ? self.date_from : i_done_date )
             i_done_date = (i_done_date >= self.date_to ? self.date_to : i_done_date )
             
@@ -488,7 +489,7 @@
             output
           when :image
             options[:image].stroke('transparent')
-            i_left = options[:subject_width] + ((version.start_date - @date_from)*options[:zoom]).floor
+            i_left = options[:subject_width] + ((version.start_date.to_date - @date_from)*options[:zoom]).floor
 
             # Make sure negative i_left doesn't overflow the subject
             if i_left > options[:subject_width]
@@ -499,7 +500,7 @@
             end
           when :pdf
             options[:pdf].SetY(options[:top]+1.5)
-            i_left = ((version.start_date - @date_from)*options[:zoom]) 
+            i_left = ((version.start_date.to_date - @date_from)*options[:zoom]) 
 
             # Make sure negative i_left doesn't overflow the subject
             if i_left > 0
@@ -580,13 +581,14 @@
             output = ''
             # Handle nil start_dates, rare but can happen.
             i_start_date =  if issue.start_date && issue.start_date >= self.date_from
-                              issue.start_date
+                              issue.start_date.to_date
                             else
                               self.date_from
                             end
 
-            i_end_date = ((issue.due_before && issue.due_before <= self.date_to) ? issue.due_before : self.date_to )
-            i_done_date = i_start_date + ((issue.due_before - i_start_date+1)*issue.done_ratio/100).floor
+			i_end_date = ((issue.due_before.to_date && issue.due_before.to_date <= self.date_to) ? issue.due_before.to_date : self.date_to )
+            debugger
+			i_done_date = i_start_date + ((issue.due_before.to_date - i_start_date+1)*issue.done_ratio/100).floor
             i_done_date = (i_done_date <= self.date_from ? self.date_from : i_done_date )
             i_done_date = (i_done_date >= self.date_to ? self.date_to : i_done_date )
             
@@ -635,8 +637,8 @@
                               @date_from
                             end
 
-            i_end_date = (issue.due_before <= date_to ? issue.due_before : date_to )        
-            i_done_date = i_start_date + ((issue.due_before - i_start_date+1)*issue.done_ratio/100).floor
+            i_end_date = (issue.due_before.to_date <= date_to ? issue.due_before.to_date : date_to )        
+            i_done_date = i_start_date + ((issue.due_before.to_date - i_start_date+1)*issue.done_ratio/100).floor
             i_done_date = (i_done_date <= @date_from ? @date_from : i_done_date )
             i_done_date = (i_done_date >= date_to ? date_to : i_done_date )        
             i_late_date = [i_end_date, Date.today].min if i_start_date < Date.today
@@ -675,9 +677,9 @@
                           @date_from
                         end
 
-            i_end_date = (issue.due_before <= @date_to ? issue.due_before : @date_to )
+            i_end_date = (issue.due_before.to_date <= @date_to ? issue.due_before.to_date : @date_to )
             
-            i_done_date = i_start_date + ((issue.due_before - i_start_date+1)*issue.done_ratio/100).floor
+            i_done_date = i_start_date + ((issue.due_before.to_date - i_start_date+1)*issue.done_ratio/100).floor
             i_done_date = (i_done_date <= @date_from ? @date_from : i_done_date )
             i_done_date = (i_done_date >= @date_to ? @date_to : i_done_date )