Impacted versions: 10.0/11.0

Steps to reproduce: go to [http://281537-11-0-12c7d3.runbot8.odoo.com](http://281537-11-0-12c7d3.runbot8.odoo.com/web?debug=1?#id=12&view_type=form&model=ir.sequence&menu_id=38&action=22) --> Settings --> Sequences --> 'Account reconcile sequence'

Current behavior: Traceback during Saving record

![](https://image.prntscr.com/image/G4x_oq6xQr2HduZQiUPDdA.png)

Change Implementation to Standard and Save the record.

![](https://image.prntscr.com/image/cv0b3Pq9SzW0Dya-zZ4cyA.png)
Expected behavior: Should Save the record

Video/Screenshot link (optional): 


def _interpolate(s, d):
            if s:
                return s % d
            return ''
        def _interpolation_dict():
            now = range_date = effective_date = datetime.now(pytz.timezone(self.env.context.get('tz') or 'UTC'))
            if self.env.context.get('ir_sequence_date'):
                effective_date = datetime.strptime(self.env.context.get('ir_sequence_date'), '%Y-%m-%d')
            if self.env.context.get('ir_sequence_date_range'):
                range_date = datetime.strptime(self.env.context.get('ir_sequence_date_range'), '%Y-%m-%d')
            sequences = {
                'year': '%Y', 'month': '%m', 'day': '%d', 'y': '%y', 'doy': '%j', 'woy': '%W',
                'weekday': '%w', 'h24': '%H', 'h12': '%I', 'min': '%M', 'sec': '%S'
            }
            res = {}
            for key, sequence in sequences.iteritems():
                res[key] = effective_date.strftime(sequence)
                res['range_' + key] = range_date.strftime(sequence)
                res['current_' + key] = now.strftime(sequence)
            return res
        d = _interpolation_dict()
        try:
            interpolated_prefix = _interpolate(self.prefix, d)
            interpolated_suffix = _interpolate(self.suffix, d)
        except ValueError:
            raise UserError(_('Invalid prefix or suffix for sequence \'%s\'') % (self.get('name')))
        return interpolated_prefix + '%%0%sd' % self.padding % number_next + interpolated_suffix
    def _create_date_range_seq(self, date):