diff --git a/tests/unit/services/command.assignment-defaults.test.ts b/tests/unit/services/command.assignment-defaults.test.ts
new file mode 100644
index 0000000..55a330c
--- /dev/null
+++ b/tests/unit/services/command.assignment-defaults.test.ts
@@ -0,0 +1,51 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { TaskService } from '../../../src/tasks/service';
+import { CommandService } from '../../../src/services/command';
+
+describe('CommandService - asignación por defecto (sin dueño vs creador)', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    TaskService.dbInstance = memdb;
+    CommandService.dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.TZ = 'Europe/Madrid';
+    memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');
+  });
+
+  it('en grupos, si no hay menciones, la tarea queda sin dueño', async () => {
+    const sender = '600111222';
+    await CommandService.handle({
+      sender,
+      groupId: '12345@g.us', // contexto grupo
+      message: '/t n tarea en grupo',
+      mentions: [],
+    });
+
+    const t = memdb.prepare(`SELECT id FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
+    const cnt = memdb.prepare(`SELECT COUNT(*) as c FROM task_assignments WHERE task_id = ?`).get(t.id) as any;
+    expect(Number(cnt.c)).toBe(0);
+  });
+
+  it('en DM, si no hay menciones, se asigna al creador', async () => {
+    const sender = '600111222';
+    await CommandService.handle({
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t n tarea en dm',
+      mentions: [],
+    });
+
+    const t = memdb.prepare(`SELECT id FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
+    const row = memdb.prepare(`SELECT user_id FROM task_assignments WHERE task_id = ?`).get(t.id) as any;
+    expect(row).toBeTruthy();
+    expect(String(row.user_id)).toBe(sender);
+  });
+});
diff --git a/tests/unit/services/command.date-parsing.test.ts b/tests/unit/services/command.date-parsing.test.ts
new file mode 100644
index 0000000..a0582b9
--- /dev/null
+++ b/tests/unit/services/command.date-parsing.test.ts
@@ -0,0 +1,91 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { TaskService } from '../../../src/tasks/service';
+import { CommandService } from '../../../src/services/command';
+
+function ymdInTZ(d: Date, tz: string = 'Europe/Madrid'): string {
+  const parts = new Intl.DateTimeFormat('en-GB', {
+    timeZone: tz,
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  }).formatToParts(d);
+  const get = (t: string) => parts.find(p => p.type === t)?.value || '';
+  return `${get('year')}-${get('month')}-${get('day')}`;
+}
+
+function addDaysToYMD(ymd: string, days: number, tz: string = 'Europe/Madrid'): string {
+  const [Y, M, D] = ymd.split('-').map(n => parseInt(n, 10));
+  const base = new Date(Date.UTC(Y, (M || 1) - 1, D || 1));
+  base.setUTCDate(base.getUTCDate() + days);
+  return ymdInTZ(base, tz);
+}
+
+describe('CommandService - parser de fechas (hoy/mañana)', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    TaskService.dbInstance = memdb;
+    CommandService.dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.TZ = 'Europe/Madrid';
+    memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');
+  });
+
+  it('interpreta "hoy" como due_date de hoy en la TZ configurada', async () => {
+    const sender = '600111222';
+    const ctx = {
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t n prueba hoy',
+      mentions: [] as string[],
+    };
+    await CommandService.handle(ctx);
+
+    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
+    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
+    expect(row).toBeTruthy();
+    expect(String(row.due_date)).toBe(todayYMD);
+  });
+
+  it('interpreta "mañana" (con o sin acento) como due_date de mañana', async () => {
+    const sender = '600111222';
+    const ctx = {
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t n prueba mañana',
+      mentions: [] as string[],
+    };
+    await CommandService.handle(ctx);
+
+    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
+    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
+    const tomorrowYMD = addDaysToYMD(todayYMD, 1, process.env.TZ);
+    expect(row).toBeTruthy();
+    expect(String(row.due_date)).toBe(tomorrowYMD);
+  });
+
+  it('elige la última fecha futura cuando hay varias (mezcla YYYY-MM-DD y tokens)', async () => {
+    const sender = '600111222';
+    const ctx = {
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      // contiene pasado (2020-01-01), hoy (futuro válido) y una futura explícita, y termina con "mañana"
+      message: '/t n mezcla 2020-01-01 hoy 2099-01-01 mañana',
+      mentions: [] as string[],
+    };
+    await CommandService.handle(ctx);
+
+    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
+    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
+    const tomorrowYMD = addDaysToYMD(todayYMD, 1, process.env.TZ);
+    expect(row).toBeTruthy();
+    expect(String(row.due_date)).toBe(tomorrowYMD);
+  });
+});
diff --git a/tests/unit/services/command.formatting-ddmm.test.ts b/tests/unit/services/command.formatting-ddmm.test.ts
new file mode 100644
index 0000000..293d2c4
--- /dev/null
+++ b/tests/unit/services/command.formatting-ddmm.test.ts
@@ -0,0 +1,36 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { TaskService } from '../../../src/tasks/service';
+import { CommandService } from '../../../src/services/command';
+
+describe('CommandService - formato dd/MM en ACK de creación', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    TaskService.dbInstance = memdb;
+    CommandService.dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.TZ = 'Europe/Madrid';
+    memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');
+  });
+
+  it('muestra la fecha como dd/MM en el ACK al creador', async () => {
+    const sender = '600111222';
+    const responses = await CommandService.handle({
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t n tarea con fecha 2099-01-05',
+      mentions: [],
+    });
+
+    const ack = responses.find(r => r.recipient === sender);
+    expect(ack).toBeTruthy();
+    expect(ack!.message).toContain('📅 05/01');
+  });
+});
diff --git a/tests/unit/services/command.help.test.ts b/tests/unit/services/command.help.test.ts
new file mode 100644
index 0000000..e167f62
--- /dev/null
+++ b/tests/unit/services/command.help.test.ts
@@ -0,0 +1,54 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { TaskService } from '../../../src/tasks/service';
+import { CommandService } from '../../../src/services/command';
+
+describe('CommandService - ayuda por DM', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    TaskService.dbInstance = memdb;
+    CommandService.dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.TZ = 'Europe/Madrid';
+  });
+
+  it('responde con ayuda cuando el usuario escribe "/t"', async () => {
+    const sender = '600111222';
+    const responses = await CommandService.handle({
+      sender,
+      groupId: '12345@g.us',
+      message: '/t',
+      mentions: [],
+    });
+
+    expect(Array.isArray(responses)).toBe(true);
+    expect(responses.length).toBe(1);
+    const r = responses[0];
+    expect(r.recipient).toBe(sender);
+    expect(r.message).toContain('Guía rápida:');
+    expect(r.message).toContain('/t ver mis');
+  });
+
+  it('responde con ayuda cuando el usuario escribe "/t ayuda"', async () => {
+    const sender = '600111222';
+    const responses = await CommandService.handle({
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t ayuda',
+      mentions: [],
+    });
+
+    expect(responses.length).toBe(1);
+    const r = responses[0];
+    expect(r.recipient).toBe(sender);
+    expect(r.message).toContain('Guía rápida:');
+    expect(r.message).toContain('/t n');
+  });
+});
diff --git a/tests/unit/services/command.listing-ddmm.test.ts b/tests/unit/services/command.listing-ddmm.test.ts
new file mode 100644
index 0000000..a2726b2
--- /dev/null
+++ b/tests/unit/services/command.listing-ddmm.test.ts
@@ -0,0 +1,46 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { TaskService } from '../../../src/tasks/service';
+import { CommandService } from '../../../src/services/command';
+
+describe('CommandService - formato dd/MM en listados', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    TaskService.dbInstance = memdb;
+    CommandService.dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.TZ = 'Europe/Madrid';
+    memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');
+  });
+
+  it('"/t ver mis" muestra fechas en dd/MM', async () => {
+    const sender = '600111222';
+
+    // Crear una tarea con due_date conocida y asignada al usuario (DM → asignada al creador)
+    await CommandService.handle({
+      sender,
+      groupId: `${sender}@s.whatsapp.net`, // DM
+      message: '/t n tarea listada 2099-01-05',
+      mentions: [],
+    });
+
+    // Listar "mis" y comprobar formato
+    const responses = await CommandService.handle({
+      sender,
+      groupId: `${sender}@s.whatsapp.net`,
+      message: '/t ver mis',
+      mentions: [],
+    });
+
+    expect(responses.length).toBe(1);
+    expect(responses[0].recipient).toBe(sender);
+    expect(responses[0].message).toContain('📅 05/01');
+  });
+});