diff --git a/addons/crm/views/crm_lead_views.xml b/addons/crm/views/crm_lead_views.xml
index ad92e946439..c6685d10551 100644
--- a/addons/crm/views/crm_lead_views.xml
+++ b/addons/crm/views/crm_lead_views.xml
@@ -558,6 +558,7 @@
                     <field name="source_id"/>
                     <field name="medium_id"/>
                     <field name="campaign_id"/>
+                    <field name="activity_state"/>
                     <separator />
                     <filter string="My Leads"
                             name="assigned_to_me"
@@ -790,6 +791,7 @@
                     <field name="country_id"/>
                     <field name="city"/>
                     <field name="phone_mobile_search"/>
+                    <field name="activity_state"/>
                     <separator/>
                     <filter string="My Pipeline" name="assigned_to_me"
                         domain="[('user_id', '=', uid)]"
diff --git a/addons/mail/models/mail_activity.py b/addons/mail/models/mail_activity.py
index 57e029db488..8d0d7ad532c 100644
--- a/addons/mail/models/mail_activity.py
+++ b/addons/mail/models/mail_activity.py
@@ -669,6 +669,7 @@ class MailActivityMixin(models.AbstractModel):
         ('today', 'Today'),
         ('planned', 'Planned')], string='Activity State',
         compute='_compute_activity_state',
+        search='_search_activity_state',
         groups="base.group_user",
         help='Status based on activities\nOverdue: Due date is already passed\n'
              'Today: Activity date is today\nPlanned: Future activities.')
@@ -735,6 +736,71 @@ class MailActivityMixin(models.AbstractModel):
             else:
                 record.activity_state = False
 
+    def _search_activity_state(self, operator, value):
+        all_states = {'overdue', 'today', 'planned', False}
+        if operator == '=':
+            search_states = {value}
+        elif operator == '!=':
+            search_states = all_states - {value}
+        elif operator == 'in':
+            search_states = set(value)
+        elif operator == 'not in':
+            search_states = all_states - set(value)
+
+        reverse_search = False
+        if False in search_states:
+            # If we search "activity_state = False", they might be a lot of records
+            # (million for some models), so instead of returning the list of IDs
+            # [(id, 'in', ids)] we will reverse the domain and return something like
+            # [(id, 'not in', ids)], so the list of ids is as small as possible
+            reverse_search = True
+            search_states = all_states - search_states
+
+        # Use number in the SQL query for performance purpose
+        integer_state_value = {
+            'overdue': -1,
+            'today': 0,
+            'planned': 1,
+            False: None,
+        }
+
+        search_states_int = {integer_state_value.get(s or False) for s in search_states}
+
+        query = """
+          SELECT res_id
+            FROM (
+                SELECT res_id,
+                       -- Global activity state
+                       MIN(
+                            -- Compute the state of each individual activities
+                            -- -1: overdue
+                            --  0: today
+                            --  1: planned
+                           SIGN(EXTRACT(day from (
+                                mail_activity.date_deadline - DATE_TRUNC('day', %(today_utc)s AT TIME ZONE res_partner.tz)
+                           )))
+                        )::INT AS activity_state
+                  FROM mail_activity
+             LEFT JOIN res_users
+                    ON res_users.id = mail_activity.user_id
+             LEFT JOIN res_partner
+                    ON res_partner.id = res_users.partner_id
+                 WHERE mail_activity.res_model = %(res_model_table)s
+              GROUP BY res_id
+            ) AS res_record
+          WHERE %(search_states_int)s @> ARRAY[activity_state]
+        """
+
+        self._cr.execute(
+            query,
+            {
+                'today_utc': pytz.UTC.localize(datetime.utcnow()),
+                'res_model_table': self._name,
+                'search_states_int': list(search_states_int)
+            },
+        )
+        return [('id', 'not in' if reverse_search else 'in', [r[0] for r in self._cr.fetchall()])]
+
     @api.depends('activity_ids.date_deadline')
     def _compute_activity_date_deadline(self):
         for record in self:
diff --git a/addons/test_mail/tests/test_mail_activity.py b/addons/test_mail/tests/test_mail_activity.py
index 64f77806164..804a5f5a397 100644
--- a/addons/test_mail/tests/test_mail_activity.py
+++ b/addons/test_mail/tests/test_mail_activity.py
@@ -9,6 +9,7 @@ from unittest.mock import DEFAULT
 import pytz
 
 from odoo import exceptions, tests
+from odoo.addons.mail.tests.common import mail_new_test_user
 from odoo.addons.test_mail.tests.common import TestMailCommon
 from odoo.addons.test_mail.models.test_mail_models import MailTestActivity
 from odoo.tools import mute_logger
@@ -218,6 +219,24 @@ class TestActivityFlow(TestActivityCommon):
 @tests.tagged('mail_activity')
 class TestActivityMixin(TestActivityCommon):
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestActivityMixin, cls).setUpClass()
+
+        cls.user_utc = mail_new_test_user(
+            cls.env,
+            name='User UTC',
+            login='User UTC',
+        )
+        cls.user_utc.tz = 'UTC'
+
+        cls.user_australia = mail_new_test_user(
+            cls.env,
+            name='user Australia',
+            login='user Australia',
+        )
+        cls.user_australia.tz = 'Australia/ACT'
+
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_activity_mixin(self):
         self.user_employee.tz = self.user_admin.tz
@@ -333,3 +352,177 @@ class TestActivityMixin(TestActivityCommon):
             user_id=self.user_admin.id,
             new_user_id=self.user_employee.id)
         self.assertEqual(rec.activity_ids[0].user_id, self.user_employee)
+
+    def test_mail_activity_state(self):
+        """Create 3 activity for 2 different users in 2 different timezones.
+
+        User UTC (+0h)
+        User Australia (+11h)
+        Today datetime: 1/1/2020 16h
+
+        Activity 1 & User UTC
+            1/1/2020 - 16h UTC       -> The state is today
+
+        Activity 2 & User Australia
+            1/1/2020 - 16h UTC
+            2/1/2020 -  1h Australia -> State is overdue
+
+        Activity 3 & User UTC
+            1/1/2020 - 23h UTC       -> The state is today
+        """
+        today_utc = datetime(2020, 1, 1, 16, 0, 0)
+
+        class MockedDatetime(datetime):
+            @classmethod
+            def utcnow(cls):
+                return today_utc
+
+        record = self.env['mail.test.activity'].create({'name': 'Record'})
+
+        with patch('odoo.addons.mail.models.mail_activity.datetime', MockedDatetime):
+            activity_1 = self.env['mail.activity'].create({
+                'summary': 'Test',
+                'activity_type_id': 1,
+                'res_model_id': self.env.ref('test_mail.model_mail_test_activity').id,
+                'res_id': record.id,
+                'date_deadline': today_utc,
+                'user_id': self.user_utc.id,
+            })
+
+            activity_2 = activity_1.copy()
+            activity_2.user_id = self.user_australia
+            activity_3 = activity_1.copy()
+            activity_3.date_deadline += relativedelta(hours=7)
+
+            self.assertEqual(activity_1.state, 'today')
+            self.assertEqual(activity_2.state, 'overdue')
+            self.assertEqual(activity_3.state, 'today')
+
+    def test_mail_activity_mixin_search_state_basic(self):
+        """Test the search method on the "activity_state".
+
+        Test all the operators and also test the case where the "activity_state" is
+        different because of the timezone. There's also a tricky case for which we
+        "reverse" the domain for performance purpose.
+        """
+        today_utc = datetime(2020, 1, 1, 16, 0, 0)
+
+        class MockedDatetime(datetime):
+            @classmethod
+            def utcnow(cls):
+                return today_utc
+
+        # Create some records without activity schedule on it for testing
+        self.env['mail.test.activity'].create([
+            {'name': 'Record %i' % record_i}
+            for record_i in range(5)
+        ])
+
+        origin_1, origin_2 = self.env['mail.test.activity'].search([], limit=2)
+
+        with patch('odoo.addons.mail.models.mail_activity.datetime', MockedDatetime):
+            origin_1_activity_1 = self.env['mail.activity'].create({
+                'summary': 'Test',
+                'activity_type_id': 1,
+                'res_model_id': self.env.ref('test_mail.model_mail_test_activity').id,
+                'res_id': origin_1.id,
+                'date_deadline': today_utc,
+                'user_id': self.user_utc.id,
+            })
+
+            origin_1_activity_2 = origin_1_activity_1.copy()
+            origin_1_activity_2.user_id = self.user_australia
+            origin_1_activity_3 = origin_1_activity_1.copy()
+            origin_1_activity_3.date_deadline += relativedelta(hours=8)
+
+            self.assertEqual(origin_1_activity_1.state, 'today')
+            self.assertEqual(origin_1_activity_2.state, 'overdue')
+            self.assertEqual(origin_1_activity_3.state, 'today')
+
+            origin_2_activity_1 = self.env['mail.activity'].create({
+                'summary': 'Test',
+                'activity_type_id': 1,
+                'res_model_id': self.env.ref('test_mail.model_mail_test_activity').id,
+                'res_id': origin_2.id,
+                'date_deadline': today_utc + relativedelta(hours=8),
+                'user_id': self.user_utc.id,
+            })
+
+            origin_2_activity_2 = origin_2_activity_1.copy()
+            origin_2_activity_2.user_id = self.user_australia
+            origin_2_activity_3 = origin_2_activity_1.copy()
+            origin_2_activity_3.date_deadline -= relativedelta(hours=8)
+            origin_2_activity_4 = origin_2_activity_1.copy()
+            origin_2_activity_4.date_deadline = datetime(2020, 1, 2, 0, 0, 0)
+
+            self.assertEqual(origin_2_activity_1.state, 'planned')
+            self.assertEqual(origin_2_activity_2.state, 'today')
+            self.assertEqual(origin_2_activity_3.state, 'today')
+            self.assertEqual(origin_2_activity_4.state, 'planned')
+
+            all_activity_mixin_record = self.env['mail.test.activity'].search([])
+
+            result = self.env['mail.test.activity'].search([('activity_state', '=', 'today')])
+            self.assertTrue(len(result) > 0)
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: p.activity_state == 'today'))
+
+            result = self.env['mail.test.activity'].search([('activity_state', 'in', ('today', 'overdue'))])
+            self.assertTrue(len(result) > 0)
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: p.activity_state in ('today', 'overdue')))
+
+            result = self.env['mail.test.activity'].search([('activity_state', 'not in', ('today',))])
+            self.assertTrue(len(result) > 0)
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: p.activity_state not in ('today',)))
+
+            result = self.env['mail.test.activity'].search([('activity_state', '=', False)])
+            self.assertTrue(len(result) >= 3, "There is more than 3 records without an activity schedule on it")
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: not p.activity_state))
+
+            result = self.env['mail.test.activity'].search([('activity_state', 'not in', ('planned', 'overdue', 'today'))])
+            self.assertTrue(len(result) >= 3, "There is more than 3 records without an activity schedule on it")
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: not p.activity_state))
+
+            # test tricky case when the domain will be reversed in the search method
+            # because of falsy value
+            result = self.env['mail.test.activity'].search([('activity_state', 'not in', ('today', False))])
+            self.assertTrue(len(result) > 0)
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: p.activity_state not in ('today', False)))
+
+            result = self.env['mail.test.activity'].search([('activity_state', 'in', ('today', False))])
+            self.assertTrue(len(result) > 0)
+            self.assertEqual(result, all_activity_mixin_record.filtered(lambda p: p.activity_state in ('today', False)))
+
+    def test_mail_activity_mixin_search_state_different_day_but_close_time(self):
+        """Test the case where there's less than 24 hours between the deadline and now_tz,
+        but one day of difference (e.g. 23h 01/01/2020 & 1h 02/02/2020). So the state
+        should be "planned" and not "today". This case was tricky to implement in SQL
+        that's why it has its own test.
+        """
+        today_utc = datetime(2020, 1, 1, 23, 0, 0)
+
+        class MockedDatetime(datetime):
+            @classmethod
+            def utcnow(cls):
+                return today_utc
+
+        # Create some records without activity schedule on it for testing
+        self.env['mail.test.activity'].create([
+            {'name': 'Record %i' % record_i}
+            for record_i in range(5)
+        ])
+
+        origin_1 = self.env['mail.test.activity'].search([], limit=1)
+
+        with patch('odoo.addons.mail.models.mail_activity.datetime', MockedDatetime):
+            origin_1_activity_1 = self.env['mail.activity'].create({
+                'summary': 'Test',
+                'activity_type_id': 1,
+                'res_model_id': self.env.ref('test_mail.model_mail_test_activity').id,
+                'res_id': origin_1.id,
+                'date_deadline': today_utc + relativedelta(hours=2),
+                'user_id': self.user_utc.id,
+            })
+
+            self.assertEqual(origin_1_activity_1.state, 'planned')
+            result = self.env['mail.test.activity'].search([('activity_state', '=', 'today')])
+            self.assertNotIn(origin_1, result, 'The activity state miss calculated during the search')