account-financial-tools/account_fiscal_month/models/res_company.py

# Copyright 2017 ACSONE SA/NV
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import api, models


class ResCompany(models.Model):

    _inherit = 'res.company'

    @api.multi
    def find_daterange_fm(self, date_str):
        self.ensure_one()
        fm_id = self.env.ref('account_fiscal_month.date_range_fiscal_month')
        return self.env['date.range'].search([
            ('type_id', '=', fm_id.id),
            ('date_start', '<=', date_str),
            ('date_end', '>=', date_str),
            '|',
            ('company_id', '=', self.id),
            ('company_id', '=', False),
        ], limit=1, order='company_id asc')