diff --git a/back/shared/i18n.ts b/back/shared/i18n.ts
index 060bbfa1..78e3e8b1 100644
--- a/back/shared/i18n.ts
+++ b/back/shared/i18n.ts
@@ -212,6 +212,9 @@ const messages: Record<string, Record<string, string>> = {
     日志设置为忽略: 'Log set to ignore',
     定时规则不能为空: 'Schedule rule cannot be empty',
     无效的定时规则: 'Invalid schedule rule',
+    定时规则必须是字符串: 'Schedule rule must be a string',
+    额外定时规则必须是对象: 'Extra schedule must be an object',
+    额外定时规则必须是数组: 'Extra schedules must be an array',
     '日志名称只能包含中文、字母、数字、下划线、连字符、点和路径分隔符':
       'Log name can only contain Chinese characters, letters, numbers, underscores, hyphens, dots, and path separators',
     日志名称不能超过100个字符: 'Log name cannot exceed 100 characters',
diff --git a/back/validation/schedule.ts b/back/validation/schedule.ts
index c6422c00..ebb669a3 100644
--- a/back/validation/schedule.ts
+++ b/back/validation/schedule.ts
@@ -20,8 +20,10 @@ export const scheduleSchema = Joi.string()
   .required()
   .custom(validateSchedule)
   .messages({
+    'any.required': '定时规则不能为空',
     'any.invalid': '无效的定时规则',
     'string.empty': '定时规则不能为空',
+    'string.base': '定时规则必须是字符串',
   });
 
 export const commonCronSchema = {
@@ -30,7 +32,27 @@ export const commonCronSchema = {
   schedule: scheduleSchema,
   labels: Joi.array().optional().allow(null),
   sub_id: Joi.number().optional().allow(null),
-  extra_schedules: Joi.array().optional().allow(null),
+  extra_schedules: Joi.array()
+    .items(
+      Joi.object({
+        schedule: Joi.string()
+          .required()
+          .custom((value, helpers) =>
+            isValidCronSchedule(value) ? value : helpers.error('any.invalid'),
+          )
+          .messages({
+            'any.required': '定时规则不能为空',
+            'any.invalid': '无效的定时规则',
+            'string.empty': '定时规则不能为空',
+            'string.base': '定时规则必须是字符串',
+          }),
+      })
+        .unknown(true)
+        .messages({ 'object.base': '额外定时规则必须是对象' }),
+    )
+    .optional()
+    .allow(null)
+    .messages({ 'array.base': '额外定时规则必须是数组' }),
   task_before: Joi.string().optional().allow('').allow(null),
   task_after: Joi.string().optional().allow('').allow(null),
   log_name: Joi.string()
diff --git a/test/back/cron-validation.test.cjs b/test/back/cron-validation.test.cjs
index ddf5f9a1..fc1e00a9 100644
--- a/test/back/cron-validation.test.cjs
+++ b/test/back/cron-validation.test.cjs
@@ -43,3 +43,127 @@ test('cron validation identifies invalid fields', () => {
     ['allow_multiple_instances'],
   );
 });
+
+test('extra schedules preserve optional values, compatible syntax and metadata', () => {
+  for (const extra_schedules of [
+    undefined,
+    null,
+    [],
+    [{ schedule: '0 6/6 * * *', remarks: 'legacy metadata' }],
+    [{ schedule: '0 0 * JAN MON#2' }, { schedule: '@hourly' }],
+  ]) {
+    const result = schema.validate({
+      command: 'task valid.js',
+      schedule: '01 7 * * *',
+      extra_schedules,
+    });
+    assert.equal(result.error, undefined, JSON.stringify(extra_schedules));
+    assert.deepEqual(result.value.extra_schedules, extra_schedules);
+  }
+  for (const schedule of ['@boot', '@once 1792245000']) {
+    assert.equal(
+      schema.validate({ command: 'task valid.js', schedule }).error,
+      undefined,
+    );
+  }
+});
+
+test('create and update reject invalid extra schedules before calling the service', async (t) => {
+  const express = require('express');
+  const { errors } = require('celebrate');
+  const load = require('../helpers/load-security-module.cjs');
+  const mutations = [];
+  const service = {
+    async create(value) {
+      mutations.push(value);
+      return { id: 1, ...value };
+    },
+    async update(value) {
+      mutations.push(value);
+      return value;
+    },
+  };
+  const route = load('back/api/cron.ts', {
+    typedi: {
+      Container: {
+        get: (key) => (key === 'logger' ? { error() {} } : service),
+      },
+    },
+    '../services/cron': class {},
+    '../services/cronView': class {},
+    '../validation/schedule': { commonCronSchema },
+    '../data/runningInstance': {},
+    '../shared/i18n': { t: (value) => value },
+    '../schedule/client': { readiness: { async ensureReady() {} } },
+  });
+  const app = express();
+  app.use(express.json());
+  route.default(app);
+  app.use(errors());
+  app.use((error, _req, res, _next) =>
+    res.status(error.status || 500).json({ message: error.message }),
+  );
+  const server = app.listen(0, '127.0.0.1');
+  await new Promise((resolve, reject) => {
+    server.once('listening', resolve);
+    server.once('error', reject);
+  });
+  t.after(() => new Promise((resolve) => server.close(resolve)));
+
+  for (const method of ['POST', 'PUT']) {
+    const payload = {
+      command: 'task valid.js',
+      schedule: '01 7 * * *',
+      ...(method === 'PUT' ? { id: 1 } : {}),
+    };
+    const request = (body) =>
+      fetch(`http://127.0.0.1:${server.address().port}/crons`, {
+        method,
+        headers: { 'content-type': 'application/json' },
+        body: JSON.stringify(body),
+      });
+    for (const extra_schedules of [
+      [{ schedule: '60 * * * *' }],
+      [{ schedule: '0 0 31 2,4 *' }],
+      [{ schedule: '' }],
+      [{ schedule: 12 }],
+      [{ schedule: '@boot' }],
+      [{ schedule: '@once 1792245000' }],
+      [{}],
+      [null],
+      ['0 * * * *'],
+      [{ schedule: '0 * * * *' }, { schedule: 'invalid' }],
+    ]) {
+      const before = mutations.length;
+      const response = await request({ ...payload, extra_schedules });
+      assert.equal(
+        response.status,
+        400,
+        `${method}: ${JSON.stringify(extra_schedules)}`,
+      );
+      const body = await response.json();
+      assert.ok(
+        body.validation.body.keys.some((key) =>
+          key.startsWith('extra_schedules.'),
+        ),
+      );
+      assert.equal(
+        mutations.length,
+        before,
+        'invalid input must not mutate tasks',
+      );
+    }
+    assert.equal(
+      (await request({ ...payload, schedule: '60 * * * *' })).status,
+      400,
+    );
+    const extra_schedules = [{ schedule: '0 6/6 * * *', remarks: 'keep' }];
+    const response = await request({ ...payload, extra_schedules });
+    assert.equal(response.status, 200);
+    assert.deepEqual(
+      (await response.json()).data.extra_schedules,
+      extra_schedules,
+    );
+  }
+  assert.equal(mutations.length, 2);
+});
diff --git a/test/back/dynamic-locales.test.cjs b/test/back/dynamic-locales.test.cjs
index 0769b419..087bf395 100644
--- a/test/back/dynamic-locales.test.cjs
+++ b/test/back/dynamic-locales.test.cjs
@@ -22,7 +22,7 @@ const {
 } = require('../../back/validation/schedule');
 const upgrade = require('../../cli/src/internal/maintenance/upgradeArtifacts.cjs');
 
-function responseFor(schema, value) {
+function responseFor(schema, value, fullResponse = false) {
   const validation = schema.validate(value).error;
   assert.ok(validation);
   const error = new CelebrateError('Validation failed', { celebrated: true });
@@ -41,7 +41,7 @@ function responseFor(schema, value) {
   validationErrors(error, {}, res, (err) => {
     throw err;
   });
-  return response.validation.body.message;
+  return fullResponse ? response : response.validation.body.message;
 }
 
 test('compiled validation schemas follow live language changes without altering field paths', () => {
@@ -75,6 +75,100 @@ test('compiled validation schemas follow live language changes without altering
   setLang('zh');
 });
 
+test('cron structure errors switch languages while retaining status and field paths', (t) => {
+  const schema = Joi.object(commonCronSchema);
+  const empty = ['定时规则不能为空', 'Schedule rule cannot be empty'];
+  const string = ['定时规则必须是字符串', 'Schedule rule must be a string'];
+  const object = ['额外定时规则必须是对象', 'Extra schedule must be an object'];
+  const array = ['额外定时规则必须是数组', 'Extra schedules must be an array'];
+  const invalid = ['无效的定时规则', 'Invalid schedule rule'];
+  const cases = [
+    [{ schedule: undefined }, 'schedule', empty],
+    [{ schedule: '' }, 'schedule', empty],
+    [{ schedule: 12 }, 'schedule', string],
+    [{ schedule: null }, 'schedule', string],
+    [{ extra_schedules: [{}] }, 'extra_schedules.0.schedule', empty],
+    [
+      { extra_schedules: [{ schedule: '' }] },
+      'extra_schedules.0.schedule',
+      empty,
+    ],
+    [
+      { extra_schedules: [{ schedule: 12 }] },
+      'extra_schedules.0.schedule',
+      string,
+    ],
+    [
+      { extra_schedules: [{ schedule: null }] },
+      'extra_schedules.0.schedule',
+      string,
+    ],
+    [
+      { extra_schedules: [{ schedule: 'invalid' }] },
+      'extra_schedules.0.schedule',
+      invalid,
+    ],
+    [
+      { extra_schedules: [{ schedule: '0 * * * *' }, {}] },
+      'extra_schedules.1.schedule',
+      empty,
+    ],
+    ...[null, '0 * * * *', 12, []].map((item) => [
+      { extra_schedules: [item] },
+      'extra_schedules.0',
+      object,
+    ]),
+    ...['0 * * * *', {}, 12].map((value) => [
+      { extra_schedules: value },
+      'extra_schedules',
+      array,
+    ]),
+  ];
+  t.after(() => setLang('zh', false));
+  for (const lang of ['en', 'zh', 'en']) {
+    setLang(lang, false);
+    for (const [value, field, messages] of cases) {
+      const response = responseFor(
+        schema,
+        {
+          command: 'task valid.js',
+          schedule: '0 * * * *',
+          ...value,
+        },
+        true,
+      );
+      assert.equal(response.statusCode, 400);
+      assert.equal(
+        response.validation.body.message,
+        messages[lang === 'zh' ? 0 : 1],
+        `${lang}: ${field}`,
+      );
+      assert.deepEqual(response.validation.body.keys, [field]);
+    }
+    const multiple = responseFor(
+      schema.prefs({ abortEarly: false }),
+      {
+        command: 'task valid.js',
+        schedule: '0 * * * *',
+        extra_schedules: [{}, { schedule: 12 }, null],
+      },
+      true,
+    );
+    assert.equal(multiple.statusCode, 400);
+    assert.equal(
+      multiple.validation.body.message,
+      [empty, string, object]
+        .map((messages) => messages[lang === 'zh' ? 0 : 1])
+        .join('. '),
+    );
+    assert.deepEqual(multiple.validation.body.keys, [
+      'extra_schedules.0.schedule',
+      'extra_schedules.1.schedule',
+      'extra_schedules.2',
+    ]);
+  }
+});
+
 test('history, upload, initialization and proxy messages resolve dynamically and preserve user text', () => {
   const keys = [
     '请先初始化',