Hello MouBou,

As per my understand, You need all invoice as per date wise not month wise right.

So you need to

1. Create one new character field

2. Update value in new char field with date which you set the filter .

3. Now set new character field group by in search view.

Example.

I have delivered date and I am getting all records as per month. Now I want to all records as per date wise. 

In python file

def _get_delivered_date(self, cr, uid, ids, fields, arg, context=None):

    result = {}

    for record in self.browse(cr, uid, ids, context=context):

        result[record.id] = record.date_delivered

    return result

_columns = {

     'new_date_delivered': fields.function(_get_delivered_date, type='char', string='New Delivered Date', store=True),

}

In xml file

<filter string="Date Delivered" name='new_date_delivered' icon="terp-personal" domain="[]" context="{'group_by':'new_date_delivered'}"/>

Hope above code help for you !!!

Cheers,

Ankit H Gandhi.