diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index b1df4fca6f4..64e62fee91a 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -1582,7 +1582,7 @@ class AccountPartialReconcile(models.Model):
                 full_to_unlink |= rec.full_reconcile_id
         #reverse the tax basis move created at the reconciliation time
         for move in self.env['account.move'].search([('tax_cash_basis_rec_id', 'in', self._ids)]):
-            if move.date > (move.company_id.period_lock_date or '0000-00-00'):
+            if move.date > (move.company_id.period_lock_date or date.min):
                 move.reverse_moves(date=move.date)
             else:
                 move.reverse_moves()
diff --git a/addons/membership/models/partner.py b/addons/membership/models/partner.py
index 5287773cd81..3a13a1e1d33 100644
--- a/addons/membership/models/partner.py
+++ b/addons/membership/models/partner.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
+from datetime import date
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError, ValidationError
 from . import membership
@@ -114,7 +115,7 @@ class Partner(models.Model):
             s = 4
             if partner.member_lines:
                 for mline in partner.member_lines:
-                    if (mline.date_to or '0000-00-00') >= today and (mline.date_from or '0000-00-00') <= today:
+                    if (mline.date_to or date.min) >= today and (mline.date_from or date.min) <= today:
                         if mline.account_invoice_line.invoice_id.partner_id == partner:
                             mstate = mline.account_invoice_line.invoice_id.state
                             if mstate == 'paid':
@@ -132,7 +133,7 @@ class Partner(models.Model):
                                 s = 3
                 if s == 4:
                     for mline in partner.member_lines:
-                        if (mline.date_from or '0000-00-00') < today and (mline.date_to or '0000-00-00') < today and (mline.date_from or '0000-00-00') <= (mline.date_to or '0000-00-00') and mline.account_invoice_line and mline.account_invoice_line.invoice_id.state == 'paid':
+                        if (mline.date_from or date.min) < today and (mline.date_to or date.min) < today and (mline.date_from or date.min) <= (mline.date_to or date.min) and mline.account_invoice_line and mline.account_invoice_line.invoice_id.state == 'paid':
                             s = 5
                         else:
                             s = 6