diff --git a/golem_activity_session/models/golem_activity_session.py b/golem_activity_session/models/golem_activity_session.py
index 8d1a82e..159f696 100644
--- a/golem_activity_session/models/golem_activity_session.py
+++ b/golem_activity_session/models/golem_activity_session.py
@@ -55,7 +55,7 @@ class GolemActivitySession(models.Model):
 
     name = fields.Char('Name', compute='_compute_name')
 
-    @api.depends('activity_id', 'weekday')
+    @api.depends('activity_id')
     def _compute_name(self):
         for s in self:
             s.name = s.activity_id.activity_name
@@ -68,12 +68,48 @@ class GolemActivitySession(models.Model):
         for s in self:
             s.places_used = len(s.member_ids)
 
-    # TODO: recurrence etc... to link with calendar.event
+    # TODO: to link with calendar.event
     activity_id = fields.Many2one('golem.activity', string='Activity',
                                   required=True)
     animator_id = fields.Many2one('res.partner', string='Animator')
+
+    @api.onchange('activity_id')
+    def onchange_activity_id(self):
+        for s in self:
+            if not s.animator_id:
+                s.animator_id = s.activity_id.animator_id
+
     is_recurrent = fields.Boolean('Is recurrent ?', default=True,
                                   help='Work in progress')
+    date_start = fields.Datetime('Start date')
+    date_end = fields.Datetime('End date')
+
+    @api.onchange('date_start')
+    def onchange_date_start(self):
+        """ Sets end date to start date if no start date """
+        for s in self:
+            if not s.date_end:
+                s.date_end = s.date_start
+
+    @api.constrains('date_start', 'date_end')
+    def _check_date_period(self):
+        """ Check if end date if after start date and if dates are included
+        into main activity period"""
+        for s in self:
+            if not s.is_recurrent:
+                if s.date_start > s.date_end:
+                    emsg = _('Start of the session cannot be after end of the '
+                             'period.')
+                    raise models.ValidationError(emsg)
+                if s.date_start < s.activity_id.date_start:
+                    emsg = _('Start of the session cannot be before the start '
+                             'of activity date')
+                    raise models.ValidationError(emsg)
+                if s.date_end > s.activity_id.date_end:
+                    emsg = _('End of the session cannot be after the end of '
+                             'activity date')
+                    raise models.ValidationError(emsg)
+
     weekday = fields.Selection([('mon', _('Monday')),
                                 ('tue', _('Tuesday')),
                                 ('wed', _('Wednesday')),
@@ -84,8 +120,15 @@ class GolemActivitySession(models.Model):
     hour_start = fields.Float('Start time')
     hour_end = fields.Float('End time')
 
+    @api.onchange('hour_start')
+    def onchange_hour_start(self):
+        """ Sets end hour to start hour if no start hour """
+        for s in self:
+            if not s.hour_end:
+                s.hour_end = s.hour_start
+
     @api.constrains('hour_start', 'hour_end')
-    def _check_period(self):
+    def _check_hour_period(self):
         """ Check if end hour if after start hour """
         for s in self:
             if s.hour_start > s.hour_end:
diff --git a/golem_activity_session/views/golem_activity_view.xml b/golem_activity_session/views/golem_activity_view.xml
index 59d420d..fd6445a 100644
--- a/golem_activity_session/views/golem_activity_view.xml
+++ b/golem_activity_session/views/golem_activity_view.xml
@@ -27,7 +27,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
         <div name="buttons" position="inside">
           <button class="oe_inline oe_stat_button" type="object"
             name="button_session" icon="fa-list">
-            <field string="Week sessions" name="session_count" widget="statinfo" />
+            <field string="Sessions" name="session_count"
+              widget="statinfo" />
           </button>
         </div>
       </field>
@@ -50,10 +51,17 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
                   attrs="{'invisible': [('is_overbooked', '=', False)]}" />
               </group>
               <group>
-                <field name="is_recurrent" readonly="True" />
-                <field name="weekday" />
-                <field name="hour_start" widget="float_time" />
-                <field name="hour_end" widget="float_time" />
+                <field name="is_recurrent" />
+                <field name="weekday"
+                  attrs="{'invisible': [('is_recurrent', '=', False)]}" />
+                <field name="hour_start" widget="float_time"
+                  attrs="{'invisible': [('is_recurrent', '=', False)]}" />
+                <field name="hour_end" widget="float_time"
+                  attrs="{'invisible': [('is_recurrent', '=', False)]}" />
+                <field name="date_start"
+                  attrs="{'invisible': [('is_recurrent', '=', True)]}" />
+                <field name="date_end"
+                  attrs="{'invisible': [('is_recurrent', '=', True)]}" />
               </group>
             </group>
             <notebook>
@@ -80,11 +88,15 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
         <tree colors="darkgrey: places_used &lt; places_min;
           red: places_remain == 0;
           orange: places_remain &lt;= 4;">
+          <field name="is_recurrent" invisible="True" />
           <field name="activity_id" />
           <field name="animator_id" />
-          <field name="weekday" string="Day" />
-          <field name="hour_start" string="Start" />
-          <field name="hour_end" string="End" />
+          <field name="weekday" string="Day"
+              attrs="{'invisible': [('is_recurrent', '=', False)]}" />
+          <field name="hour_start" string="Hour"
+              attrs="{'invisible': [('is_recurrent', '=', False)]}" />
+          <field name="date_start" string="Date"
+              attrs="{'invisible': [('is_recurrent', '=', True)]}" />
           <field name="places" />
           <field name="places_min" string="Min." />
           <field name="places_remain" string="Remain" />