diff --git a/product/ERP5/PropertySheet/Task.py b/product/ERP5/PropertySheet/Task.py
index 38a34257ab0104ee6d33a0b071b6c2abc497bb00..e4077940f1272718a76563be7ceda38455495578 100755
--- a/product/ERP5/PropertySheet/Task.py
+++ b/product/ERP5/PropertySheet/Task.py
@@ -47,6 +47,7 @@ class Task:
         {   'id'          : 'start_date',
             'description' : 'The date which the movement starts',
             'type'        : 'date',
+            'range'       : True,
             'default'     : None,
             'acquisition_base_category'     : ('delivery', 'order', 'parent',),
             'acquisition_portal_type'       : Expression('python: portal.getPortalAcquisitionMovementTypeList() + portal.getPortalDeliveryTypeList() + portal.getPortalOrderTypeList() + portal.getPortalInvoiceTypeList()'),
@@ -59,6 +60,7 @@ class Task:
         {   'id'          : 'stop_date',
             'description' : 'The date which the movement stops',
             'type'        : 'date',
+            'range'       : True,
             'default'     : None,
             'acquisition_base_category'     : ('delivery', 'order', 'parent',),
             'acquisition_portal_type'       : Expression('python: portal.getPortalAcquisitionMovementTypeList() + portal.getPortalDeliveryTypeList() + portal.getPortalOrderTypeList() + portal.getPortalInvoiceTypeList()'),