diff --git a/addons/web/static/src/js/fields/basic_fields.js b/addons/web/static/src/js/fields/basic_fields.js
index 5a3bd699a7c..344f7174c54 100644
--- a/addons/web/static/src/js/fields/basic_fields.js
+++ b/addons/web/static/src/js/fields/basic_fields.js
@@ -482,6 +482,7 @@ var FieldMonetary = InputField.extend({
      * @override
      * @private
      * @param {float} value
+     * @returns {string}
      */
     _formatValue: function (value) {
         var format = field_utils.format[this.mode === 'edit' ? "float" : "monetary"];
@@ -598,6 +599,10 @@ var FieldBoolean = AbstractField.extend({
 var FieldInteger = InputField.extend({
     supportedFieldTypes: ['integer'],
 
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
     /**
      * For integer fields, 0 is a valid value.
      *
@@ -606,6 +611,34 @@ var FieldInteger = InputField.extend({
     isSet: function () {
         return this.value === 0 || this._super.apply(this, arguments);
     },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * Format integer value
+     *
+     * Note: We have to overwrite this method to allow virtual ids. A virtual id
+     * is a character string composed of an integer and has a dash and other
+     * information.
+     * E.g: in calendar, the recursive event have virtual id linked to a real id
+     * virtual event id "23-20170418020000" is linked to the event id 23
+     *
+     * @override
+     * @private
+     * @param {integer|string} value
+     * @returns {string}
+     */
+    _formatValue: function (value) {
+        if (typeof value === 'string') {
+            if (!/^[0-9]+-/.test(value)) {
+                throw new Error('"' + value + '" is not an integer or a virtual id');
+            }
+            return value;
+        }
+        return field_utils.format.integer(value, this.field);
+    },
 });
 
 var FieldFloat = InputField.extend({
diff --git a/addons/web/static/src/js/views/calendar/calendar_model.js b/addons/web/static/src/js/views/calendar/calendar_model.js
index ef35fee0ca2..1aa4ee9e838 100644
--- a/addons/web/static/src/js/views/calendar/calendar_model.js
+++ b/addons/web/static/src/js/views/calendar/calendar_model.js
@@ -292,7 +292,7 @@ return AbstractModel.extend({
         return this._rpc({
             model: this.modelName,
             method: 'write',
-            args: [record.id, data],
+            args: [[record.id], data],
         });
     },
 
diff --git a/addons/web/static/tests/fields/basic_fields_tests.js b/addons/web/static/tests/fields/basic_fields_tests.js
index cd0380d0949..9f2ff12c9e2 100644
--- a/addons/web/static/tests/fields/basic_fields_tests.js
+++ b/addons/web/static/tests/fields/basic_fields_tests.js
@@ -1521,6 +1521,31 @@ QUnit.module('basic_fields', {
         form.destroy();
     });
 
+    QUnit.test('integer field in form view with virtual id', function(assert) {
+        assert.expect(2);
+        var params = {
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch:'<form string="Partners"><field name="id"/></form>',
+        };
+
+        params.res_id = this.data.partner.records[1].id = "2-20170808020000";
+        var form = createView(params);
+        assert.strictEqual(form.$('.o_form_field').text(), "2-20170808020000",
+            "Should display virtual id");
+        form.destroy();
+
+        params.res_id = this.data.partner.records[1].id = "2.65-20170808020000";
+        try {
+            form = createView(params);
+        } catch (error) {
+            assert.strictEqual(error.message, '"2.65-20170808020000" is not an integer or a virtual id',
+                "Should throw an exception because it's a wrong value");
+        }
+        form.destroy();
+    });
+
     QUnit.test('integer field in editable list view', function (assert) {
         assert.expect(4);