fix(task-repeat): allow selecting day-of-month recurrence (#8896)

* fix(task-repeat): allow selecting day-of-month mode

* fix(task-repeat): clarify monthly recurrence pattern

* test(task-repeat): cover day-of-month persistence

* docs(task-repeat): explain custom monthly patterns

docs/wiki/2.06-Manage-Repeating-Tasks.md

@@ -27,6 +27,7 @@ You can also open the dialog from a repeating task instance or from a repeat pro
    - Schedule type (only for intervals > 1): Fixed schedule (every X from start date) or After completion (X after I finish).
    - Start date — when the pattern begins (required).
    - For weekly cycle: check the weekdays (Monday–Sunday) on which the task should recur.
+   - For monthly cycle: choose a **Monthly pattern**. **Day of month** uses the day shown in **Start date**; first, second, third, fourth, and last patterns also require a **Weekday**.
 5. Optionally set **Tags to add** (chip list).
 6. Optionally set **Scheduled start time** (e.g. 15:00; leave blank for all-day). If you set a time, **Remind at** appears — choose when to be reminded (e.g. when it starts, 5 minutes before).
 7. Optionally set **Default Estimate** (duration). **Order** (number) controls creation order when several recurring tasks are created at the same time; see the field description in the dialog.

src/app/features/task-repeat-cfg/dialog-edit-task-repeat-cfg/dialog-edit-task-repeat-cfg.component.spec.ts

@@ -7,7 +7,10 @@ import {
   MatDialogRef,
 } from '@angular/material/dialog';
 import { DateAdapter, MatNativeDateModule } from '@angular/material/core';
+import { MatFormFieldHarness } from '@angular/material/form-field/testing';
+import { MatSelectHarness } from '@angular/material/select/testing';
 import { NoopAnimationsModule } from '@angular/platform-browser/animations';
+import { TestbedHarnessEnvironment } from '@angular/cdk/testing/testbed';
 import { TranslateModule } from '@ngx-translate/core';
 import { provideMockStore } from '@ngrx/store/testing';
 import { Observable, of, Subject } from 'rxjs';
@@ -74,6 +77,7 @@ describe('DialogEditTaskRepeatCfgComponent', () => {
     getRepeatCfgReturnValue?:
       | Observable<TaskRepeatCfg | undefined>
       | Subject<TaskRepeatCfg>,
+    renderTemplate = false,
   ): Promise<ComponentFixture<DialogEditTaskRepeatCfgComponent>> => {
     mockDialogRef = jasmine.createSpyObj('MatDialogRef', ['close']);
     mockMatDialog = jasmine.createSpyObj('MatDialog', ['open']);
@@ -117,7 +121,7 @@ describe('DialogEditTaskRepeatCfgComponent', () => {
       formatTime: () => '12:00 PM',
     });
 
-    await TestBed.configureTestingModule({
+    const testModule = TestBed.configureTestingModule({
       imports: [
         DialogEditTaskRepeatCfgComponent,
         MatDialogModule,
@@ -140,16 +144,20 @@ describe('DialogEditTaskRepeatCfgComponent', () => {
         { provide: DateService, useValue: mockDateService },
         { provide: DateAdapter, useClass: CustomDateAdapter },
       ],
-    })
-      .overrideComponent(DialogEditTaskRepeatCfgComponent, {
+    });
+
+    if (!renderTemplate) {
+      testModule.overrideComponent(DialogEditTaskRepeatCfgComponent, {
         set: {
           // Use a minimal template to avoid @ngx-formly/material select rendering,
           // which triggers a compareWith validation error with Angular Material 21+.
           // These tests verify component signals/logic, not template rendering.
           template: '<div></div>',
         },
-      })
-      .compileComponents();
+      });
+    }
+
+    await testModule.compileComponents();
 
     return TestBed.createComponent(DialogEditTaskRepeatCfgComponent);
   };
@@ -158,6 +166,72 @@ describe('DialogEditTaskRepeatCfgComponent', () => {
     TestBed.resetTestingModule();
   });
 
+  it('keeps Day of month selected after switching from an Nth weekday (#8886)', async () => {
+    const monthlyNthWeekdayCfg: TaskRepeatCfg = {
+      ...DEFAULT_TASK_REPEAT_CFG,
+      id: 'repeat-cfg-monthly-nth-weekday',
+      title: 'Monthly task',
+      quickSetting: 'CUSTOM',
+      repeatCycle: 'MONTHLY',
+      startDate: '2026-06-09',
+      monthlyWeekOfMonth: 2,
+      monthlyWeekday: 1,
+    };
+    const fixture = await setupTestBed(
+      { repeatCfg: monthlyNthWeekdayCfg },
+      undefined,
+      true,
+    );
+    fixture.detectChanges();
+    await fixture.whenStable();
+
+    const loader = TestbedHarnessEnvironment.loader(fixture);
+    const selects = await loader.getAllHarnesses(MatSelectHarness);
+    const formFieldsBeforeSwitch = await loader.getAllHarnesses(MatFormFieldHarness);
+    const labelsBeforeSwitch = await Promise.all(
+      formFieldsBeforeSwitch.map((formField) => formField.getLabel()),
+    );
+    expect(labelsBeforeSwitch).toContain(T.F.TASK_REPEAT.F.WEEKDAY);
+    let monthlyPatternSelect: MatSelectHarness | undefined;
+    let dayOfMonthOptionText = '';
+
+    for (const select of selects) {
+      await select.open();
+      const [dayOfMonthOption] = await select.getOptions({
+        text: /MONTHLY_MODE_DAY_OF_MONTH/,
+      });
+      if (dayOfMonthOption) {
+        monthlyPatternSelect = select;
+        dayOfMonthOptionText = await dayOfMonthOption.getText();
+        await dayOfMonthOption.click();
+        break;
+      }
+      await select.close();
+    }
+
+    expect(monthlyPatternSelect).toBeDefined();
+    expect(await monthlyPatternSelect!.getValueText()).toBe(dayOfMonthOptionText);
+
+    fixture.detectChanges();
+    await fixture.whenStable();
+
+    expect(fixture.componentInstance.repeatCfg().monthlyWeekOfMonth).toBeNull();
+    const formFieldsAfterSwitch = await loader.getAllHarnesses(MatFormFieldHarness);
+    const labelsAfterSwitch = await Promise.all(
+      formFieldsAfterSwitch.map((formField) => formField.getLabel()),
+    );
+    expect(labelsAfterSwitch).not.toContain(T.F.TASK_REPEAT.F.WEEKDAY);
+
+    fixture.componentInstance.save();
+
+    const changes =
+      mockTaskRepeatCfgService.updateTaskRepeatCfg.calls.mostRecent().args[1];
+    expect(
+      Object.prototype.hasOwnProperty.call(changes, 'monthlyWeekOfMonth'),
+    ).toBeTrue();
+    expect(changes.monthlyWeekOfMonth).toBeUndefined();
+  });
+
   describe('isLoading signal', () => {
     it('should be false when repeatCfg is provided directly (sync path)', async () => {
       const fixture = await setupTestBed({ repeatCfg: mockRepeatCfg });

src/app/features/task-repeat-cfg/dialog-edit-task-repeat-cfg/dialog-edit-task-repeat-cfg.component.ts

@@ -57,6 +57,7 @@ import { getDateTimeFromClockString } from '../../../util/get-date-time-from-clo
 import { remindOptionToMilliseconds } from '../../tasks/util/remind-option-to-milliseconds';
 import { isValidSplitTime } from '../../../util/is-valid-split-time';
 import { DateService } from '../../../core/date/date.service';
+import { MAT_SELECT_CONFIG } from '@angular/material/select';
 
 // Fields whose change requires offering "Update all task instances?" — covers
 // what propagates to existing tasks (vs. schedule fields, which only affect
@@ -88,6 +89,12 @@ const WEEKDAY_KEYS: (keyof TaskRepeatCfgCopy)[] = [
   templateUrl: './dialog-edit-task-repeat-cfg.component.html',
   styleUrls: ['./dialog-edit-task-repeat-cfg.component.scss'],
   changeDetection: ChangeDetectionStrategy.OnPush,
+  providers: [
+    {
+      provide: MAT_SELECT_CONFIG,
+      useValue: { canSelectNullableOptions: true },
+    },
+  ],
   imports: [
     MatDialogTitle,
     TranslatePipe,

src/app/features/task-repeat-cfg/dialog-edit-task-repeat-cfg/task-repeat-cfg-form.const.spec.ts

@@ -2,6 +2,7 @@ import {
   TASK_REPEAT_CFG_ADVANCED_FORM_CFG,
   TASK_REPEAT_CFG_ESSENTIAL_FORM_CFG,
 } from './task-repeat-cfg-form.const';
+import { T } from '../../../t.const';
 
 describe('TaskRepeatCfgFormConfig', () => {
   it('should not contain startDate in essential form fields', () => {
@@ -23,6 +24,22 @@ describe('TaskRepeatCfgFormConfig', () => {
     expect(remindAtField).toBeUndefined();
   });
 
+  it('explains that Day of month uses the start date (#8886)', () => {
+    const repeatContainer = TASK_REPEAT_CFG_ESSENTIAL_FORM_CFG.find(
+      (field) => field.fieldGroupClassName === 'repeat-config-container',
+    );
+    const monthlyAnchor = repeatContainer?.fieldGroup?.find(
+      (field) => field.fieldGroupClassName === 'monthly-anchor',
+    );
+    const monthlyPattern = monthlyAnchor?.fieldGroup?.find(
+      (field) => field.key === 'monthlyWeekOfMonth',
+    );
+
+    expect(monthlyPattern?.templateOptions?.description).toBe(
+      T.F.TASK_REPEAT.F.MONTHLY_MODE_DAY_OF_MONTH_DESCRIPTION,
+    );
+  });
+
   describe('weekdays group visibility (issue #8025)', () => {
     const repeatContainer = TASK_REPEAT_CFG_ESSENTIAL_FORM_CFG.find(
       (field) => field.fieldGroupClassName === 'repeat-config-container',

src/app/features/task-repeat-cfg/dialog-edit-task-repeat-cfg/task-repeat-cfg-form.const.ts

@@ -95,6 +95,7 @@ export const TASK_REPEAT_CFG_ESSENTIAL_FORM_CFG: FormlyFieldConfig[] = [
             defaultValue: null,
             templateOptions: {
               label: T.F.TASK_REPEAT.F.WEEK_OF_MONTH,
+              description: T.F.TASK_REPEAT.F.MONTHLY_MODE_DAY_OF_MONTH_DESCRIPTION,
               options: [
                 { value: null, label: T.F.TASK_REPEAT.F.MONTHLY_MODE_DAY_OF_MONTH },
                 { value: 1, label: T.F.TASK_REPEAT.F.ORD_FIRST },

src/app/t.const.ts

@@ -2054,6 +2054,8 @@ const T = {
         INHERIT_SUBTASKS_DESCRIPTION: 'F.TASK_REPEAT.F.INHERIT_SUBTASKS_DESCRIPTION',
         MONDAY: 'F.TASK_REPEAT.F.MONDAY',
         MONTHLY_MODE_DAY_OF_MONTH: 'F.TASK_REPEAT.F.MONTHLY_MODE_DAY_OF_MONTH',
+        MONTHLY_MODE_DAY_OF_MONTH_DESCRIPTION:
+          'F.TASK_REPEAT.F.MONTHLY_MODE_DAY_OF_MONTH_DESCRIPTION',
         NOTES: 'F.TASK_REPEAT.F.NOTES',
         ORD_FIRST: 'F.TASK_REPEAT.F.ORD_FIRST',
         ORD_FIRST_NTH: 'F.TASK_REPEAT.F.ORD_FIRST_NTH',

src/assets/i18n/en.json

@@ -1997,6 +1997,7 @@
         "INHERIT_SUBTASKS_DESCRIPTION": "When enabled, subtasks from the most recent task instance will be recreated with the recurring task",
         "MONDAY": "Monday",
         "MONTHLY_MODE_DAY_OF_MONTH": "Day of month",
+        "MONTHLY_MODE_DAY_OF_MONTH_DESCRIPTION": "\"Day of month\" uses the day shown in Start date.",
         "NOTES": "Default notes",
         "ORD_FIRST": "first",
         "ORD_FIRST_NTH": "first",
@@ -2038,7 +2039,7 @@
         "WAIT_FOR_COMPLETION": "Only create next task after completion",
         "WAIT_FOR_COMPLETION_DESCRIPTION": "Prevents multiple pending recurring tasks from piling up. The next instance will only be created once the current task is completed",
         "WEDNESDAY": "Wednesday",
-        "WEEK_OF_MONTH": "Week of month",
+        "WEEK_OF_MONTH": "Monthly pattern",
         "WEEKDAY": "Weekday",
         "WEEKDAY_REQUIRED": "Select at least one weekday"
       },