diff --git a/addons/calendar/models/calendar_event.py b/addons/calendar/models/calendar_event.py
index 4570465ffce..0f2468b47b3 100644
--- a/addons/calendar/models/calendar_event.py
+++ b/addons/calendar/models/calendar_event.py
@@ -196,13 +196,13 @@ class Meeting(models.Model):
         help="Repeat every (Days/Week/Month/Year)")
     count = fields.Integer(
         string='Repeat', help="Repeat x times", compute='_compute_recurrence', readonly=False)
-    mo = fields.Boolean('Mon', compute='_compute_recurrence', readonly=False)
-    tu = fields.Boolean('Tue', compute='_compute_recurrence', readonly=False)
-    we = fields.Boolean('Wed', compute='_compute_recurrence', readonly=False)
-    th = fields.Boolean('Thu', compute='_compute_recurrence', readonly=False)
-    fr = fields.Boolean('Fri', compute='_compute_recurrence', readonly=False)
-    sa = fields.Boolean('Sat', compute='_compute_recurrence', readonly=False)
-    su = fields.Boolean('Sun', compute='_compute_recurrence', readonly=False)
+    mon = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    tue = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    wed = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    thu = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    fri = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    sat = fields.Boolean(compute='_compute_recurrence', readonly=False)
+    sun = fields.Boolean(compute='_compute_recurrence', readonly=False)
     month_by = fields.Selection(
         MONTH_BY_SELECTION, string='Option', compute='_compute_recurrence', readonly=False)
     day = fields.Integer('Date of month', compute='_compute_recurrence', readonly=False)
@@ -908,8 +908,8 @@ class Meeting(models.Model):
     @api.model
     def _get_recurrent_fields(self):
         return {'byday', 'until', 'rrule_type', 'month_by', 'event_tz', 'rrule',
-                'interval', 'count', 'end_type', 'mo', 'tu', 'we', 'th', 'fr', 'sa',
-                'su', 'day', 'weekday'}
+                'interval', 'count', 'end_type', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat',
+                'sun', 'day', 'weekday'}
 
     @api.model
     def _get_time_fields(self):
diff --git a/addons/calendar/models/calendar_recurrence.py b/addons/calendar/models/calendar_recurrence.py
index c7bddeb7634..160b87dbed3 100644
--- a/addons/calendar/models/calendar_recurrence.py
+++ b/addons/calendar/models/calendar_recurrence.py
@@ -30,15 +30,17 @@ RRULE_FREQ_TO_SELECT = {
 }
 
 RRULE_WEEKDAY_TO_FIELD = {
-    rrule.MO.weekday: 'mo',
-    rrule.TU.weekday: 'tu',
-    rrule.WE.weekday: 'we',
-    rrule.TH.weekday: 'th',
-    rrule.FR.weekday: 'fr',
-    rrule.SA.weekday: 'sa',
-    rrule.SU.weekday: 'su',
+    rrule.MO.weekday: 'mon',
+    rrule.TU.weekday: 'tue',
+    rrule.WE.weekday: 'wed',
+    rrule.TH.weekday: 'thu',
+    rrule.FR.weekday: 'fri',
+    rrule.SA.weekday: 'sat',
+    rrule.SU.weekday: 'sun',
 }
 
+RRULE_WEEKDAYS = {'SUN': 'SU', 'MON': 'MO', 'TUE': 'TU', 'WED': 'WE', 'THU': 'TH', 'FRI': 'FR', 'SAT': 'SA'}
+
 RRULE_TYPE_SELECTION = [
     ('daily', 'Days'),
     ('weekly', 'Weeks'),
@@ -58,13 +60,13 @@ MONTH_BY_SELECTION = [
 ]
 
 WEEKDAY_SELECTION = [
-    ('MO', 'Monday'),
-    ('TU', 'Tuesday'),
-    ('WE', 'Wednesday'),
-    ('TH', 'Thursday'),
-    ('FR', 'Friday'),
-    ('SA', 'Saturday'),
-    ('SU', 'Sunday'),
+    ('MON', 'Monday'),
+    ('TUE', 'Tuesday'),
+    ('WED', 'Wednesday'),
+    ('THU', 'Thursday'),
+    ('FRI', 'Friday'),
+    ('SAT', 'Saturday'),
+    ('SUN', 'Sunday'),
 ]
 
 BYDAY_SELECTION = [
@@ -104,13 +106,13 @@ class RecurrenceRule(models.Model):
     end_type = fields.Selection(END_TYPE_SELECTION, default='count')
     interval = fields.Integer(default=1)
     count = fields.Integer(default=1)
-    mo = fields.Boolean()
-    tu = fields.Boolean()
-    we = fields.Boolean()
-    th = fields.Boolean()
-    fr = fields.Boolean()
-    sa = fields.Boolean()
-    su = fields.Boolean()
+    mon = fields.Boolean()
+    tue = fields.Boolean()
+    wed = fields.Boolean()
+    thu = fields.Boolean()
+    fri = fields.Boolean()
+    sat = fields.Boolean()
+    sun = fields.Boolean()
     month_by = fields.Selection(MONTH_BY_SELECTION, default='date')
     day = fields.Integer(default=1)
     weekday = fields.Selection(WEEKDAY_SELECTION, string='Weekday')
@@ -160,7 +162,7 @@ class RecurrenceRule(models.Model):
 
     @api.depends(
         'byday', 'until', 'rrule_type', 'month_by', 'interval', 'count', 'end_type',
-        'mo', 'tu', 'we', 'th', 'fr', 'sa', 'su', 'day', 'weekday')
+        'mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun', 'day', 'weekday')
     def _compute_rrule(self):
         for recurrence in self:
             recurrence.rrule = recurrence._rrule_serialize()
@@ -302,7 +304,7 @@ class RecurrenceRule(models.Model):
     def _rrule_parse(self, rule_str, date_start):
         # LUL TODO clean this mess
         data = {}
-        day_list = ['mo', 'tu', 'we', 'th', 'fr', 'sa', 'su']
+        day_list = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
 
         if 'Z' in rule_str and not date_start.tzinfo:
             date_start = pytz.utc.localize(date_start)
@@ -432,13 +434,13 @@ class RecurrenceRule(models.Model):
         return tuple(
             rrule.weekday(weekday_index)
             for weekday_index, weekday in {
-                rrule.MO.weekday: self.mo,
-                rrule.TU.weekday: self.tu,
-                rrule.WE.weekday: self.we,
-                rrule.TH.weekday: self.th,
-                rrule.FR.weekday: self.fr,
-                rrule.SA.weekday: self.sa,
-                rrule.SU.weekday: self.su,
+                rrule.MO.weekday: self.mon,
+                rrule.TU.weekday: self.tue,
+                rrule.WE.weekday: self.wed,
+                rrule.TH.weekday: self.thu,
+                rrule.FR.weekday: self.fri,
+                rrule.SA.weekday: self.sat,
+                rrule.SU.weekday: self.sun,
             }.items() if weekday
         )
 
@@ -458,7 +460,7 @@ class RecurrenceRule(models.Model):
         if freq == 'monthly' and self.month_by == 'date':  # e.g. every 15th of the month
             rrule_params['bymonthday'] = self.day
         elif freq == 'monthly' and self.month_by == 'day':  # e.g. every 2nd Monday in the month
-            rrule_params['byweekday'] = getattr(rrule, self.weekday)(int(self.byday))  # e.g. MO(+2) for the second Monday of the month
+            rrule_params['byweekday'] = getattr(rrule, RRULE_WEEKDAYS[self.weekday])(int(self.byday))  # e.g. MO(+2) for the second Monday of the month
         elif freq == 'weekly':
             weekdays = self._get_week_days()
             if not weekdays:
diff --git a/addons/calendar/tests/test_calendar_recurrent_event_case2.py b/addons/calendar/tests/test_calendar_recurrent_event_case2.py
index 036bbc0a0c4..af5ffec13a9 100644
--- a/addons/calendar/tests/test_calendar_recurrent_event_case2.py
+++ b/addons/calendar/tests/test_calendar_recurrent_event_case2.py
@@ -38,11 +38,11 @@ class TestRecurrentEvent(common.TransactionCase):
             'duration': 1.0,
             'until': '2011-04-30',
             'end_type': 'end_date',
-            'fr': True,
-            'mo': True,
-            'th': True,
-            'tu': True,
-            'we': True,
+            'fri': True,
+            'mon': True,
+            'thu': True,
+            'tue': True,
+            'wed': True,
             'name': 'Review code with programmer',
             'recurrency': True,
             'rrule_type': 'weekly'
diff --git a/addons/calendar/tests/test_event_recurrence.py b/addons/calendar/tests/test_event_recurrence.py
index 5e2375a1a87..ea857fdfb85 100644
--- a/addons/calendar/tests/test_event_recurrence.py
+++ b/addons/calendar/tests/test_event_recurrence.py
@@ -43,7 +43,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         """ Every week, on Tuesdays, for 3 occurences """
         detached_events = self.event._apply_recurrence_values({
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'interval': 1,
             'count': 3,
             'event_tz': 'UTC',
@@ -63,7 +63,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 2,
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'count': 2,
             'event_tz': 'UTC',
         })
@@ -81,7 +81,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 2,
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'count': 2,
             'event_tz': 'UTC',
         })
@@ -96,7 +96,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
     def test_weekly_until(self):
         self.event._apply_recurrence_values({
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'interval': 2,
             'end_type': 'end_date',
             'until': datetime(2019, 11, 15),
@@ -156,7 +156,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
             'interval': 2,
             'month_by': 'day',
             'byday': '3',
-            'weekday': 'TU',
+            'weekday': 'TUE',
             'end_type': 'end_date',
             'until': date(2020, 3, 15),
             'event_tz': 'UTC',
@@ -176,7 +176,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
             'interval': 2,
             'rrule_type': 'monthly',
             'month_by': 'day',
-            'weekday': 'WE',
+            'weekday': 'WED',
             'byday': '-1',
             'end_type': 'end_date',
             'until': date(2020, 1, 15),
@@ -211,7 +211,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 2,
             'rrule_type': 'weekly',
-            'mo': True,
+            'mon': True,
             'count': '2',
             'event_tz': 'US/Eastern',  # DST change on 2002/10/27
         })
@@ -232,7 +232,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 1,
             'rrule_type': 'weekly',
-            'su': True,
+            'sun': True,
             'count': '2',
             'event_tz': 'US/Eastern'  # DST change on 2002/4/7
         })
@@ -254,7 +254,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 1,
             'rrule_type': 'weekly',
-            'su': True,
+            'sun': True,
             'count': '2',
             'event_tz': 'US/Eastern'  # DST change on 2002/4/7
         })
@@ -276,7 +276,7 @@ class TestCreateRecurrentEvents(TestRecurrentEvents):
         self.event._apply_recurrence_values({
             'interval': 1,
             'rrule_type': 'weekly',
-            'mo': True,
+            'mon': True,
             'count': 2,
             'event_tz': 'Europe/Brussels'  # DST change on 2020/3/23
         })
@@ -298,7 +298,7 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
             'stop': datetime(2019, 10, 24, 18, 0),
             'recurrency': True,
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'interval': 1,
             'count': 3,
             'event_tz': 'Etc/GMT-4',
@@ -322,8 +322,8 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
         self.assertNotEqual(self.recurrence, new_recurrence)
         self.assertEqual(new_recurrence.count, 2)
         self.assertEqual(new_recurrence.dtstart, datetime(2019, 11, 2, 1, 0))
-        self.assertFalse(new_recurrence.tu)
-        self.assertTrue(new_recurrence.sa)
+        self.assertFalse(new_recurrence.tue)
+        self.assertTrue(new_recurrence.sat)
         self.assertEventDates(new_recurrence.calendar_event_ids, [
             (datetime(2019, 11, 2, 1, 0), datetime(2019, 11, 5, 18, 0)),
             (datetime(2019, 11, 9, 1, 0), datetime(2019, 11, 12, 18, 0)),
@@ -340,8 +340,8 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
         self.assertFalse(self.recurrence.exists())
         self.assertEqual(new_recurrence.count, 3)
         self.assertEqual(new_recurrence.dtstart, datetime(2019, 10, 26, 1, 0))
-        self.assertFalse(new_recurrence.tu)
-        self.assertTrue(new_recurrence.sa)
+        self.assertFalse(new_recurrence.tue)
+        self.assertTrue(new_recurrence.sat)
         self.assertEventDates(new_recurrence.calendar_event_ids, [
             (datetime(2019, 10, 26, 1, 0), datetime(2019, 10, 29, 18, 0)),
             (datetime(2019, 11, 2, 1, 0), datetime(2019, 11, 5, 18, 0)),
@@ -374,8 +374,8 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
     def test_change_week_day_rrule(self):
         recurrence = self.events.recurrence_id
         recurrence.rrule = 'FREQ=WEEKLY;COUNT=3;BYDAY=WE' # from TU to WE
-        self.assertFalse(self.recurrence.tu)
-        self.assertTrue(self.recurrence.we)
+        self.assertFalse(self.recurrence.tue)
+        self.assertTrue(self.recurrence.wed)
 
     def test_shift_all_base_inactive(self):
         self.recurrence.base_event_id.active = False
@@ -406,7 +406,7 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
         event = self.events[1]
         event.write({
             'recurrence_update': 'future_events',
-            'fr': True,  # recurrence is now Tuesday AND Friday
+            'fri': True,  # recurrence is now Tuesday AND Friday
             'count': 4,
         })
         self.assertEventDates(self.recurrence.calendar_event_ids, [
@@ -425,14 +425,14 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
         self.assertEqual(events[2], self.events[2], "Events on Tuesdays should not have changed")
         self.assertNotEqual(events.recurrence_id, self.recurrence, "Events should no longer be linked to the original recurrence")
         self.assertEqual(events.recurrence_id.count, 4, "The new recurrence should have 4")
-        self.assertTrue(event.recurrence_id.tu)
-        self.assertTrue(event.recurrence_id.fr)
+        self.assertTrue(event.recurrence_id.tue)
+        self.assertTrue(event.recurrence_id.fri)
 
     def test_update_recurrence_all(self):
         with self.assertRaises(UserError):
             self.events[1].write({
                 'recurrence_update': 'all_events',
-                'mo': True,  # recurrence is now Tuesday AND Monday
+                'mon': True,  # recurrence is now Tuesday AND Monday
             })
 
     def test_shift_single(self):
@@ -484,7 +484,7 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
             'stop_date': datetime(2019, 10, 24),
             'recurrency': True,
             'rrule_type': 'weekly',
-            'tu': True,
+            'tue': True,
             'interval': 1,
             'count': 3,
             'event_tz': 'Etc/GMT-4',
@@ -506,8 +506,8 @@ class TestUpdateRecurrentEvents(TestRecurrentEvents):
         self.assertNotEqual(recurrence, new_recurrence)
         self.assertEqual(new_recurrence.count, 2)
         self.assertEqual(new_recurrence.dtstart, datetime(2019, 11, 2, 8, 0))
-        self.assertFalse(new_recurrence.tu)
-        self.assertTrue(new_recurrence.sa)
+        self.assertFalse(new_recurrence.tue)
+        self.assertTrue(new_recurrence.sat)
         self.assertEventDates(new_recurrence.calendar_event_ids, [
             (datetime(2019, 11, 2, 8, 0), datetime(2019, 11, 5, 18, 0)),
             (datetime(2019, 11, 9, 8, 0), datetime(2019, 11, 12, 18, 0)),
@@ -527,8 +527,8 @@ class TestUpdateMultiDayWeeklyRecurrentEvents(TestRecurrentEvents):
             'stop': datetime(2019, 10, 24, 18, 0),
             'recurrency': True,
             'rrule_type': 'weekly',
-            'tu': True,
-            'fr': True,
+            'tue': True,
+            'fri': True,
             'interval': 1,
             'count': 3,
             'event_tz': 'Etc/GMT-4',
@@ -564,11 +564,11 @@ class TestUpdateMultiDayWeeklyRecurrentEvents(TestRecurrentEvents):
             'start': event.start + relativedelta(days=3),
             'stop': event.stop + relativedelta(days=3),
         })
-        self.assertTrue(self.recurrence.fr)
-        self.assertTrue(self.recurrence.tu)
-        self.assertTrue(event.recurrence_id.tu)
-        self.assertTrue(event.recurrence_id.mo)
-        self.assertFalse(event.recurrence_id.fr)
+        self.assertTrue(self.recurrence.fri)
+        self.assertTrue(self.recurrence.tue)
+        self.assertTrue(event.recurrence_id.tue)
+        self.assertTrue(event.recurrence_id.mon)
+        self.assertFalse(event.recurrence_id.fri)
         self.assertEqual(event.recurrence_id.count, 2)
 
 
@@ -586,7 +586,7 @@ class TestUpdateMonthlyByDay(TestRecurrentEvents):
             'interval': 1,
             'count': 3,
             'month_by': 'day',
-            'weekday': 'TU',
+            'weekday': 'TUE',
             'byday': '3',
             'event_tz': 'Etc/GMT-4',
         })
diff --git a/addons/calendar/views/calendar_views.xml b/addons/calendar/views/calendar_views.xml
index e5496704d36..d02418f5f37 100644
--- a/addons/calendar/views/calendar_views.xml
+++ b/addons/calendar/views/calendar_views.xml
@@ -180,13 +180,13 @@
                                             </div>
                                         </group>
                                         <group attrs="{'invisible': [('rrule_type', '!=', 'weekly')]}" name="weekdays">
-                                            <field name="mo"/>
-                                            <field name="tu"/>
-                                            <field name="we"/>
-                                            <field name="th"/>
-                                            <field name="fr"/>
-                                            <field name="sa"/>
-                                            <field name="su"/>
+                                            <field name="mon"/>
+                                            <field name="tue"/>
+                                            <field name="wed"/>
+                                            <field name="thu"/>
+                                            <field name="fri"/>
+                                            <field name="sat"/>
+                                            <field name="sun"/>
                                         </group>
                                         <group attrs="{'invisible': [('rrule_type', '!=', 'monthly')]}">
                                             <label string="Day of Month" for="month_by"/>
diff --git a/addons/lunch/models/lunch_alert.py b/addons/lunch/models/lunch_alert.py
index 41cbcab8e5c..91c77e55116 100644
--- a/addons/lunch/models/lunch_alert.py
+++ b/addons/lunch/models/lunch_alert.py
@@ -12,7 +12,7 @@ from textwrap import dedent
 from odoo.addons.base.models.res_partner import _tz_get
 
 _logger = logging.getLogger(__name__)
-WEEKDAY_TO_NAME = ['monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday']
+WEEKDAY_TO_NAME = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
 CRON_DEPENDS = {'name', 'active', 'mode', 'until', 'notification_time', 'notification_moment', 'tz'}
 
 
@@ -42,13 +42,13 @@ class LunchAlert(models.Model):
     cron_id = fields.Many2one('ir.cron', ondelete='cascade', required=True, readonly=True)
 
     until = fields.Date('Show Until')
-    recurrency_monday = fields.Boolean('Monday', default=True)
-    recurrency_tuesday = fields.Boolean('Tuesday', default=True)
-    recurrency_wednesday = fields.Boolean('Wednesday', default=True)
-    recurrency_thursday = fields.Boolean('Thursday', default=True)
-    recurrency_friday = fields.Boolean('Friday', default=True)
-    recurrency_saturday = fields.Boolean('Saturday', default=True)
-    recurrency_sunday = fields.Boolean('Sunday', default=True)
+    mon = fields.Boolean(default=True)
+    tue = fields.Boolean(default=True)
+    wed = fields.Boolean(default=True)
+    thu = fields.Boolean(default=True)
+    fri = fields.Boolean(default=True)
+    sat = fields.Boolean(default=True)
+    sun = fields.Boolean(default=True)
 
     available_today = fields.Boolean('Is Displayed Today',
                                      compute='_compute_available_today', search='_search_available_today')
@@ -63,12 +63,10 @@ class LunchAlert(models.Model):
             'Notification time must be between 0 and 12')
     ]
 
-    @api.depends('recurrency_monday', 'recurrency_tuesday', 'recurrency_wednesday',
-                 'recurrency_thursday', 'recurrency_friday', 'recurrency_saturday',
-                 'recurrency_sunday')
+    @api.depends('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
     def _compute_available_today(self):
         today = fields.Date.context_today(self)
-        fieldname = 'recurrency_%s' % (WEEKDAY_TO_NAME[today.weekday()])
+        fieldname = WEEKDAY_TO_NAME[today.weekday()]
 
         for alert in self:
             alert.available_today = alert.until > today if alert.until else True and alert[fieldname]
@@ -79,7 +77,7 @@ class LunchAlert(models.Model):
 
         searching_for_true = (operator == '=' and value) or (operator == '!=' and not value)
         today = fields.Date.context_today(self)
-        fieldname = 'recurrency_%s' % (WEEKDAY_TO_NAME[today.weekday()])
+        fieldname = WEEKDAY_TO_NAME[today.weekday()]
 
         return expression.AND([
             [(fieldname, operator, value)],
diff --git a/addons/lunch/models/lunch_supplier.py b/addons/lunch/models/lunch_supplier.py
index 28e923de70a..bb9ace17fa8 100644
--- a/addons/lunch/models/lunch_supplier.py
+++ b/addons/lunch/models/lunch_supplier.py
@@ -13,7 +13,7 @@ from odoo.tools import float_round
 from odoo.addons.base.models.res_partner import _tz_get
 
 
-WEEKDAY_TO_NAME = ['monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday']
+WEEKDAY_TO_NAME = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
 CRON_DEPENDS = {'name', 'active', 'send_by', 'automatic_email_time', 'moment', 'tz'}
 
 def float_to_time(hours, moment='am', tz=None):
@@ -62,13 +62,13 @@ class LunchSupplier(models.Model):
     automatic_email_time = fields.Float('Order Time', default=12.0, required=True)
     cron_id = fields.Many2one('ir.cron', ondelete='cascade', required=True, readonly=True)
 
-    recurrency_monday = fields.Boolean('Monday', default=True)
-    recurrency_tuesday = fields.Boolean('Tuesday', default=True)
-    recurrency_wednesday = fields.Boolean('Wednesday', default=True)
-    recurrency_thursday = fields.Boolean('Thursday', default=True)
-    recurrency_friday = fields.Boolean('Friday', default=True)
-    recurrency_saturday = fields.Boolean('Saturday')
-    recurrency_sunday = fields.Boolean('Sunday')
+    mon = fields.Boolean(default=True)
+    tue = fields.Boolean(default=True)
+    wed = fields.Boolean(default=True)
+    thu = fields.Boolean(default=True)
+    fri = fields.Boolean(default=True)
+    sat = fields.Boolean()
+    sun = fields.Boolean()
 
     recurrency_end_date = fields.Date('Until', help="This field is used in order to ")
 
@@ -206,9 +206,7 @@ class LunchSupplier(models.Model):
 
         orders.action_confirm()
 
-    @api.depends('recurrency_end_date', 'recurrency_monday', 'recurrency_tuesday',
-                 'recurrency_wednesday', 'recurrency_thursday', 'recurrency_friday',
-                 'recurrency_saturday', 'recurrency_sunday')
+    @api.depends('recurrency_end_date', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
     def _compute_available_today(self):
         now = fields.Datetime.now().replace(tzinfo=pytz.UTC)
 
@@ -218,7 +216,7 @@ class LunchSupplier(models.Model):
             if supplier.recurrency_end_date and now.date() >= supplier.recurrency_end_date:
                 supplier.available_today = False
             else:
-                fieldname = 'recurrency_%s' % (WEEKDAY_TO_NAME[now.weekday()])
+                fieldname = WEEKDAY_TO_NAME[now.weekday()]
                 supplier.available_today = supplier[fieldname]
 
     def _search_available_today(self, operator, value):
@@ -228,7 +226,7 @@ class LunchSupplier(models.Model):
         searching_for_true = (operator == '=' and value) or (operator == '!=' and not value)
 
         now = fields.Datetime.now().replace(tzinfo=pytz.UTC).astimezone(pytz.timezone(self.env.user.tz or 'UTC'))
-        fieldname = 'recurrency_%s' % (WEEKDAY_TO_NAME[now.weekday()])
+        fieldname = WEEKDAY_TO_NAME[now.weekday()]
 
         recurrency_domain = expression.OR([
             [('recurrency_end_date', '=', False)],
diff --git a/addons/lunch/populate/lunch.py b/addons/lunch/populate/lunch.py
index 5e490b82ed0..9686084e913 100644
--- a/addons/lunch/populate/lunch.py
+++ b/addons/lunch/populate/lunch.py
@@ -91,13 +91,13 @@ class LunchSupplier(models.Model):
             ('active', populate.cartesian([True, False])),
             ('send_by', populate.cartesian(['phone', 'mail'])),
             ('delivery', populate.cartesian(['delivery', 'no_delivery'])),
-            ('recurrency_monday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_tuesday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_wednesday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_thursday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_friday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_saturday', populate.iterate([False, True], [0.9, 0.1])),
-            ('recurrency_sunday', populate.iterate([False, True], [0.9, 0.1])),
+            ('mon', populate.iterate([True, False], [0.9, 0.1])),
+            ('tue', populate.iterate([True, False], [0.9, 0.1])),
+            ('wed', populate.iterate([True, False], [0.9, 0.1])),
+            ('thu', populate.iterate([True, False], [0.9, 0.1])),
+            ('fri', populate.iterate([True, False], [0.9, 0.1])),
+            ('sat', populate.iterate([False, True], [0.9, 0.1])),
+            ('sun', populate.iterate([False, True], [0.9, 0.1])),
             ('available_location_ids', populate.iterate(
                 [[], [(6, 0, location_ids)]],
                 then=populate.compute(get_location_ids))),
@@ -150,13 +150,13 @@ class LunchAlert(models.Model):
             ('active', populate.cartesian([True, False])),
             ('recipients', populate.cartesian(['everyone', 'last_week', 'last_month', 'last_year'])),
             ('mode', populate.iterate(['alert', 'chat'])),
-            ('recurrency_monday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_tuesday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_wednesday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_thursday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_friday', populate.iterate([True, False], [0.9, 0.1])),
-            ('recurrency_saturday', populate.iterate([False, True], [0.9, 0.1])),
-            ('recurrency_sunday', populate.iterate([False, True], [0.9, 0.1])),
+            ('mon', populate.iterate([True, False], [0.9, 0.1])),
+            ('tue', populate.iterate([True, False], [0.9, 0.1])),
+            ('wed', populate.iterate([True, False], [0.9, 0.1])),
+            ('thu', populate.iterate([True, False], [0.9, 0.1])),
+            ('fri', populate.iterate([True, False], [0.9, 0.1])),
+            ('sat', populate.iterate([False, True], [0.9, 0.1])),
+            ('sun', populate.iterate([False, True], [0.9, 0.1])),
             ('name', populate.constant('alert_{counter}')),
             ('message', populate.constant('<strong>alert message {counter}</strong>')),
             ('notification_time', populate.randfloat(0, 12)),
diff --git a/addons/lunch/tests/test_supplier.py b/addons/lunch/tests/test_supplier.py
index e24c0c74806..49be5e1b960 100644
--- a/addons/lunch/tests/test_supplier.py
+++ b/addons/lunch/tests/test_supplier.py
@@ -56,10 +56,10 @@ env['lunch.supplier'].browse([{self.supplier_kothai.id}])._send_auto_email()""")
         self.env.user.tz = 'Europe/Brussels'
         Supplier = self.env['lunch.supplier']
 
-        tests = [(self.monday_1am, 1.0, 'monday'), (self.monday_10am, 10.0, 'monday'),
-                 (self.monday_1pm, 13.0, 'monday'), (self.monday_8pm, 20.0, 'monday'),
-                 (self.saturday_3am, 3.0, 'saturday'), (self.saturday_10am, 10.0, 'saturday'),
-                 (self.saturday_1pm, 13.0, 'saturday'), (self.saturday_8pm, 20.0, 'saturday')]
+        tests = [(self.monday_1am, 1.0, 'mon'), (self.monday_10am, 10.0, 'mon'),
+                 (self.monday_1pm, 13.0, 'mon'), (self.monday_8pm, 20.0, 'mon'),
+                 (self.saturday_3am, 3.0, 'sat'), (self.saturday_10am, 10.0, 'sat'),
+                 (self.saturday_1pm, 13.0, 'sat'), (self.saturday_8pm, 20.0, 'sat')]
 
         # It should return an empty domain if we compare to values other than datetime
         assert Supplier._search_available_today('>', 7) == []
@@ -69,7 +69,7 @@ env['lunch.supplier'].browse([{self.supplier_kothai.id}])._send_auto_email()""")
             with patch.object(fields.Datetime, 'now', return_value=value) as _:
                 assert Supplier._search_available_today('=', True) == ['&', '|', ('recurrency_end_date', '=', False),
                         ('recurrency_end_date', '>', value.replace(tzinfo=pytz.UTC).astimezone(pytz.timezone(self.env.user.tz))),
-                        ('recurrency_%s' % (dayname), '=', True)],\
+                        (dayname, '=', True)],\
                         'Wrong domain generated for values (%s, %s)' % (value, rvalue)
 
         with patch.object(fields.Datetime, 'now', return_value=self.monday_10am) as _:
diff --git a/addons/lunch/views/lunch_alert_views.xml b/addons/lunch/views/lunch_alert_views.xml
index 22eb5d7a62b..8745d571f78 100644
--- a/addons/lunch/views/lunch_alert_views.xml
+++ b/addons/lunch/views/lunch_alert_views.xml
@@ -49,13 +49,13 @@
                             <field name="active" widget="boolean_toggle"/>
                         </group>
                         <group>
-                            <field name="recurrency_monday"/>
-                            <field name="recurrency_tuesday"/>
-                            <field name="recurrency_wednesday"/>
-                            <field name="recurrency_thursday"/>
-                            <field name="recurrency_friday"/>
-                            <field name="recurrency_saturday"/>
-                            <field name="recurrency_sunday"/>
+                            <field name="mon"/>
+                            <field name="tue"/>
+                            <field name="wed"/>
+                            <field name="thu"/>
+                            <field name="fri"/>
+                            <field name="sat"/>
+                            <field name="sun"/>
                             <label for="notification_time" attrs="{'invisible': [['mode', '!=', 'chat']]}"/>
                             <div class="o_row" attrs="{'invisible': [['mode', '!=', 'chat']]}">
                                 <field name="notification_time" attrs="{'required': [('mode', '=', 'chat')]}" widget="float_time"/>
diff --git a/addons/lunch/views/lunch_supplier_views.xml b/addons/lunch/views/lunch_supplier_views.xml
index 1519d182e33..ba0ec6e7228 100644
--- a/addons/lunch/views/lunch_supplier_views.xml
+++ b/addons/lunch/views/lunch_supplier_views.xml
@@ -47,13 +47,13 @@
                     <group>
                         <group string="Availability">
                             <field name="tz" groups="base.group_no_one"/>
-                            <field name="recurrency_monday"/>
-                            <field name="recurrency_tuesday"/>
-                            <field name="recurrency_wednesday"/>
-                            <field name="recurrency_thursday"/>
-                            <field name="recurrency_friday"/>
-                            <field name="recurrency_saturday"/>
-                            <field name="recurrency_sunday"/>
+                            <field name="mon"/>
+                            <field name="tue"/>
+                            <field name="wed"/>
+                            <field name="thu"/>
+                            <field name="fri"/>
+                            <field name="sat"/>
+                            <field name="sun"/>
                             <field name="recurrency_end_date" groups="base.group_no_one"/>
                         </group>
                         <group string="Orders">
diff --git a/addons/microsoft_calendar/models/calendar.py b/addons/microsoft_calendar/models/calendar.py
index 65af30e45ff..233f53e544d 100644
--- a/addons/microsoft_calendar/models/calendar.py
+++ b/addons/microsoft_calendar/models/calendar.py
@@ -312,13 +312,13 @@ class Meeting(models.Model):
             if recurrence.month_by == 'day' or recurrence.rrule_type == 'weekly':
                 pattern['daysOfWeek'] = [
                     weekday_name for weekday_name, weekday in {
-                        'monday': recurrence.mo,
-                        'tuesday': recurrence.tu,
-                        'wednesday': recurrence.we,
-                        'thursday': recurrence.th,
-                        'friday': recurrence.fr,
-                        'saturday': recurrence.sa,
-                        'sunday': recurrence.su,
+                        'monday': recurrence.mon,
+                        'tuesday': recurrence.tue,
+                        'wednesday': recurrence.wed,
+                        'thursday': recurrence.thu,
+                        'friday': recurrence.fri,
+                        'saturday': recurrence.sat,
+                        'sunday': recurrence.sun,
                     }.items() if weekday]
                 pattern['firstDayOfWeek'] = 'sunday'
 
diff --git a/addons/microsoft_calendar/utils/microsoft_event.py b/addons/microsoft_calendar/utils/microsoft_event.py
index 2234b1ad6a9..c21e3484e6e 100644
--- a/addons/microsoft_calendar/utils/microsoft_event.py
+++ b/addons/microsoft_calendar/utils/microsoft_event.py
@@ -192,7 +192,7 @@ class MicrosoftEvent(abc.Set):
             result['month_by'] = month_by
 
         week_days = [x[:2] for x in pattern.get('daysOfWeek', [])]
-        for week_day in ['mo', 'tu', 'we', 'th', 'fr', 'sa', 'su']:
+        for week_day in ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']:
             result[week_day] = week_day in week_days
         if week_days:
             result['weekday'] = week_days[0].upper()