diff --git a/addons/web/static/tests/helpers/mock_server.js b/addons/web/static/tests/helpers/mock_server.js
index d247637e682..5f79066c810 100644
--- a/addons/web/static/tests/helpers/mock_server.js
+++ b/addons/web/static/tests/helpers/mock_server.js
@@ -775,7 +775,7 @@ export class MockServer {
                 if (aggregateFunction === "day") {
                     return date.toFormat("yyyy-MM-dd");
                 } else if (aggregateFunction === "week") {
-                    return `W${date.toFormat("WW yyyy")}`;
+                    return `W${date.toFormat("WW kkkk")}`;
                 } else if (aggregateFunction === "quarter") {
                     return `Q${date.toFormat("q yyyy")}`;
                 } else if (aggregateFunction === "year") {
@@ -837,6 +837,9 @@ export class MockServer {
                     } else if (aggregateFunction === "year") {
                         startDate = parseDate(val, { format: "y" });
                         endDate = startDate.plus({ years: 1 });
+                    } else if (aggregateFunction === "quarter") {
+                        startDate = parseDate(val, { format: "q yyyy" });
+                        endDate = startDate.plus({ quarters: 1 });
                     } else {
                         startDate = parseDate(val, { format: "MMMM yyyy" });
                         endDate = startDate.plus({ months: 1 });
diff --git a/addons/web/static/tests/mock_server_tests.js b/addons/web/static/tests/mock_server_tests.js
index ee8deddd368..d09b907c205 100644
--- a/addons/web/static/tests/mock_server_tests.js
+++ b/addons/web/static/tests/mock_server_tests.js
@@ -27,6 +27,25 @@ QUnit.module("Mock Server", {
                         { id: 2, name: "Raoul", email: "raoul@example.com", active: false },
                     ],
                 },
+                bar: {
+                    fields: {
+                        foo: {
+                            string: "Foo",
+                            type: "integer",
+                            searchable: true,
+                            group_operator: "sum",
+                        },
+                        date: { string: "Date", type: "date", store: true, sortable: true },
+                    },
+                    records: [
+                        { id: 1, foo: 12, date: "2016-12-14" },
+                        { id: 2, foo: 1, date: "2016-10-26" },
+                        { id: 3, foo: 17, date: "2016-12-15" },
+                        { id: 4, foo: 2, date: "2016-04-11" },
+                        { id: 5, foo: 22, date: "2016-12-15" },
+                        { id: 6, foo: 42, date: "2019-12-30" },
+                    ],
+                },
             },
         };
     },
@@ -94,3 +113,102 @@ QUnit.test("performRPC: search_read with active_test=true", async function (asse
     });
     assert.deepEqual(result, [{ id: 1, name: "Jean-Michel" }]);
 });
+
+QUnit.test("performRPC: read_group, group by date", async function (assert) {
+    assert.expect(10);
+    const server = new MockServer(this.data, {});
+    let result = await server.performRPC("", {
+        model: "bar",
+        method: "read_group",
+        args: [[]],
+        kwargs: {
+            fields: ["foo"],
+            domain: [],
+            groupby: ["date"], //Month by default
+        },
+    });
+    assert.deepEqual(
+        result.map((x) => x.date),
+        ["December 2016", "October 2016", "April 2016", "December 2019"]
+    );
+    assert.deepEqual(
+        result.map((x) => x.date_count),
+        [3, 1, 1, 1]
+    );
+
+    result = await server.performRPC("", {
+        model: "bar",
+        method: "read_group",
+        args: [[]],
+        kwargs: {
+            fields: ["foo"],
+            domain: [],
+            groupby: ["date:day"],
+        },
+    });
+    assert.deepEqual(
+        result.map((x) => x["date:day"]),
+        ["2016-12-14", "2016-10-26", "2016-12-15", "2016-04-11", "2019-12-30"]
+    );
+    assert.deepEqual(
+        result.map((x) => x.date_count),
+        [1, 1, 2, 1, 1]
+    );
+
+    result = await server.performRPC("", {
+        model: "bar",
+        method: "read_group",
+        args: [[]],
+        kwargs: {
+            fields: ["foo"],
+            domain: [],
+            groupby: ["date:week"],
+        },
+    });
+    assert.deepEqual(
+        result.map((x) => x["date:week"]),
+        ["W50 2016", "W43 2016", "W15 2016", "W01 2020"]
+    );
+    assert.deepEqual(
+        result.map((x) => x.date_count),
+        [3, 1, 1, 1]
+    );
+
+    result = await server.performRPC("", {
+        model: "bar",
+        method: "read_group",
+        args: [[]],
+        kwargs: {
+            fields: ["foo"],
+            domain: [],
+            groupby: ["date:quarter"],
+        },
+    });
+    assert.deepEqual(
+        result.map((x) => x["date:quarter"]),
+        ["Q4 2016", "Q2 2016", "Q4 2019"]
+    );
+    assert.deepEqual(
+        result.map((x) => x.date_count),
+        [4, 1, 1]
+    );
+
+    result = await server.performRPC("", {
+        model: "bar",
+        method: "read_group",
+        args: [[]],
+        kwargs: {
+            fields: ["foo"],
+            domain: [],
+            groupby: ["date:year"],
+        },
+    });
+    assert.deepEqual(
+        result.map((x) => x["date:year"]),
+        ["2016", "2019"]
+    );
+    assert.deepEqual(
+        result.map((x) => x.date_count),
+        [5, 1]
+    );
+});