diff --git a/addons/account_budget/account_budget.py b/addons/account_budget/account_budget.py
index 7d9666ae5ac..de354f8c878 100644
--- a/addons/account_budget/account_budget.py
+++ b/addons/account_budget/account_budget.py
@@ -111,7 +111,7 @@ class crossovered_budget_lines(osv.osv):
     def _prac_amt(self, cr, uid, ids, context=None):
         res = {}
         result = 0.0
-        if context is None: 
+        if context is None:
             context = {}
         for line in self.browse(cr, uid, ids, context=context):
             acc_ids = [x.id for x in line.general_budget_id.account_ids]
@@ -141,7 +141,7 @@ class crossovered_budget_lines(osv.osv):
 
     def _theo_amt(self, cr, uid, ids, context=None):
         res = {}
-        if context is None: 
+        if context is None:
             context = {}
         for line in self.browse(cr, uid, ids, context=context):
             today = datetime.datetime.today()
@@ -202,6 +202,22 @@ class crossovered_budget_lines(osv.osv):
         'company_id': fields.related('crossovered_budget_id', 'company_id', type='many2one', relation='res.company', string='Company', store=True, readonly=True)
     }
 
+    def _check_budget_lines(self, cr, uid, ids, context=None):
+        current_budget_line = self.browse(cr, uid, ids, context=context)[0]
+        obj_budget_ids = self.search(cr, uid, [('general_budget_id', '=', current_budget_line.general_budget_id.id)], context=context)
+        obj_budget_ids.remove(ids[0])
+        data_budget_yr = self.browse(cr, uid, obj_budget_ids, context=context)
+
+        for old_line in data_budget_yr:
+            if old_line.general_budget_id.id == current_budget_line['general_budget_id'].id:
+                if old_line.date_from <= current_budget_line['date_from'] <= old_line.date_to or \
+                    old_line.date_from <= current_budget_line['date_to'] <= old_line.date_to:
+                    return False
+        return True
+    _constraints = [
+        (_check_budget_lines, 'Error! You can not define overlapping budget lines for the same budgetary position.',['date_from', 'date_to'])
+    ]
+
 crossovered_budget_lines()
 
 class account_analytic_account(osv.osv):
diff --git a/addons/account_budget/account_budget_demo.xml b/addons/account_budget/account_budget_demo.xml
index 487c7b9eb93..d93e78e3448 100644
--- a/addons/account_budget/account_budget_demo.xml
+++ b/addons/account_budget/account_budget_demo.xml
@@ -47,15 +47,15 @@
             <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
             <field eval="-500.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-01-31'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_1" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_consultancy"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-02-01'" name="date_from"/>
             <field eval="-250.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-02-28'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_2" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_consultancy"/>
@@ -63,124 +63,124 @@
             <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
             <field eval="500.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-01-31'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_3" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_consultancy"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-07'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-02-07'" name="date_from"/>
             <field eval="900.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-02-28'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_4" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_consultancy"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-03-01'" name="date_from"/>
             <field eval="300.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-06'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-03-15'" name="date_to"/>
         </record>
     </data>
     <data noupdate="1">
         <record id="crossovered_budget_lines_5" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_super_product_trainings"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-09-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-03-16'" name="date_from"/>
             <field eval="375.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
             <field eval="str(time.localtime(time.time())[0]+1)+'-12-03'" name="paid_date"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-03-31'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_6" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_super_product_trainings"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-09-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-04-01'" name="date_from"/>
             <field eval="-150.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-04-30'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_7" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_super_product_trainings"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-09-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-05-01'" name="date_from"/>
             <field eval="375.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
             <field eval="str(time.localtime(time.time())[0]+1)+'-12-03'" name="paid_date"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-05-31'" name="date_to"/>
         </record>
     </data>
     <data noupdate="1">
         <record id="crossovered_budget_lines_8" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p1"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-06-01'" name="date_from"/>
             <field eval="-7500.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-06-15'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_9" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p1"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-06-16'" name="date_from"/>
             <field eval="-5000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-06-30'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_10" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p1"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-07-01'" name="date_from"/>
             <field eval="-2000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-07-15'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_11" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p1"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-07-16'" name="date_from"/>
             <field eval="20000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-07-31'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_12" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p1"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-08-01'" name="date_from"/>
             <field eval="20000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-08-15'" name="date_to"/>
         </record>
     </data>
     <data noupdate="1">
         <record id="crossovered_budget_lines_13" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p2"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-08-16'" name="date_from"/>
             <field eval="-3000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-08-31'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_14" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p2"/>
             <field name="general_budget_id" ref="account_budget_post_purchase0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-09-01'" name="date_from"/>
             <field eval="-1000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-09-15'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_15" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p2"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-09-16'" name="date_from"/>
             <field eval="10000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetpessimistic0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-09-30'" name="date_to"/>
         </record>
         <record id="crossovered_budget_lines_16" model="crossovered.budget.lines">
             <field name="analytic_account_id" ref="account.analytic_seagate_p2"/>
             <field name="general_budget_id" ref="account_budget_post_sales0"/>
-            <field eval="str(time.localtime(time.time())[0]+1)+'-01-01'" name="date_from"/>
+            <field eval="str(time.localtime(time.time())[0]+1)+'-10-01'" name="date_from"/>
             <field eval="10000.0" name="planned_amount"/>
             <field name="crossovered_budget_id" ref="crossovered_budget_budgetoptimistic0"/>
             <field eval="str(time.localtime(time.time())[0]+1)+'-12-31'" name="date_to"/>