diff --git a/mrp_multi_level/__manifest__.py b/mrp_multi_level/__manifest__.py
index 01ffcda84..09bad48d2 100644
--- a/mrp_multi_level/__manifest__.py
+++ b/mrp_multi_level/__manifest__.py
@@ -3,7 +3,7 @@
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
 {
     'name': 'MRP Multi Level',
-    'version': '11.0.1.0.0',
+    'version': '11.0.1.0.1',
     'development_status': 'Beta',
     'license': 'AGPL-3',
     'author': 'Ucamco, '
diff --git a/mrp_multi_level/readme/HISTORY.rst b/mrp_multi_level/readme/HISTORY.rst
new file mode 100644
index 000000000..743376125
--- /dev/null
+++ b/mrp_multi_level/readme/HISTORY.rst
@@ -0,0 +1,10 @@
+11.0.1.0.1 (2018-08-03)
+~~~~~~~~~~~~~~~~~~~~~~~
+
+* [FIX] User and system locales doesn't break MRP calculation.
+  (`#290 <https://github.com/OCA/manufacture/pull/290>`_)
+
+11.0.1.0.0 (2018-07-09)
+~~~~~~~~~~~~~~~~~~~~~~~
+
+* Start of the history.
diff --git a/mrp_multi_level/wizards/mrp_multi_level.py b/mrp_multi_level/wizards/mrp_multi_level.py
index 5015ed666..0d1f35e3d 100644
--- a/mrp_multi_level/wizards/mrp_multi_level.py
+++ b/mrp_multi_level/wizards/mrp_multi_level.py
@@ -7,6 +7,7 @@ from odoo import api, fields, models, exceptions, _
 from odoo.tools import DEFAULT_SERVER_DATETIME_FORMAT
 from odoo.tools import DEFAULT_SERVER_DATE_FORMAT
 from datetime import date, datetime, timedelta
+import locale
 import logging
 
 logger = logging.getLogger(__name__)
@@ -637,11 +638,25 @@ class MultiLevelMrp(models.TransientModel):
 
         logger.info('END MRP CALCULATION')
 
+    @api.model
+    def _convert_group_date_to_default(self, group_date):
+        """Odoo read_group time format include the month as locale’s
+        abbreviated name (%b). Using 'en_GB' as common language for read_group
+        calls and this conversion avoids possible issues with locales."""
+        lc = locale.setlocale(locale.LC_TIME)
+        try:
+            locale.setlocale(locale.LC_TIME, 'en_GB.UTF-8')
+            return datetime.strptime(
+                group_date, ODOO_READ_GROUP_DAY_FORMAT).strftime(
+                DEFAULT_SERVER_DATE_FORMAT)
+        finally:
+            locale.setlocale(locale.LC_TIME, lc)
+
     @api.model
     def _init_mrp_inventory(self, mrp_product):
         mrp_move_obj = self.env['mrp.move']
         # Read Demand
-        demand_groups = mrp_move_obj.read_group(
+        demand_groups = mrp_move_obj.with_context(lang='en_GB').read_group(
             [('mrp_product_id', '=', mrp_product.id),
              ('mrp_type', '=', 'd')],
             ['mrp_date', 'mrp_qty'], ['mrp_date:day'],
@@ -649,13 +664,12 @@ class MultiLevelMrp(models.TransientModel):
         demand_qty_by_date = {}
         for group in demand_groups:
             # Reformat date back to default server format.
-            group_date = datetime.strptime(
-                group['mrp_date:day'], ODOO_READ_GROUP_DAY_FORMAT).strftime(
-                DEFAULT_SERVER_DATE_FORMAT)
+            group_date = self._convert_group_date_to_default(
+                group['mrp_date:day'])
             demand_qty_by_date[group_date] = group['mrp_qty']
 
         # Read Supply
-        supply_groups = mrp_move_obj.read_group(
+        supply_groups = mrp_move_obj.with_context(lang='en_GB').read_group(
             [('mrp_product_id', '=', mrp_product.id),
              ('mrp_type', '=', 's'),
              ('mrp_action', '=', 'none')],
@@ -664,16 +678,15 @@ class MultiLevelMrp(models.TransientModel):
         supply_qty_by_date = {}
         for group in supply_groups:
             # Reformat date back to default server format.
-            group_date = datetime.strptime(
-                group['mrp_date:day'], ODOO_READ_GROUP_DAY_FORMAT).strftime(
-                DEFAULT_SERVER_DATE_FORMAT)
+            group_date = self._convert_group_date_to_default(
+                group['mrp_date:day'])
             supply_qty_by_date[group_date] = group['mrp_qty']
 
         # Read supply actions
         # TODO: if we remove cancel take it into account here,
         # TODO: as well as mrp_type ('r').
         exclude_mrp_actions = ['none', 'cancel']
-        action_groups = mrp_move_obj.read_group(
+        action_groups = mrp_move_obj.with_context(lang='en_GB').read_group(
             [('mrp_product_id', '=', mrp_product.id),
              ('mrp_qty', '!=', 0.0),
              ('mrp_type', '=', 's'),
@@ -683,9 +696,8 @@ class MultiLevelMrp(models.TransientModel):
         supply_actions_qty_by_date = {}
         for group in action_groups:
             # Reformat date back to default server format.
-            group_date = datetime.strptime(
-                group['mrp_date:day'], ODOO_READ_GROUP_DAY_FORMAT).strftime(
-                DEFAULT_SERVER_DATE_FORMAT)
+            group_date = self._convert_group_date_to_default(
+                group['mrp_date:day'])
             supply_actions_qty_by_date[group_date] = group['mrp_qty']
 
         # Dates