diff --git a/docs/api/cozy-client/interfaces/manifest.FrequencyOptions.md b/docs/api/cozy-client/interfaces/manifest.FrequencyOptions.md
new file mode 100644
index 0000000000..850e448b07
--- /dev/null
+++ b/docs/api/cozy-client/interfaces/manifest.FrequencyOptions.md
@@ -0,0 +1,55 @@
+[cozy-client](../README.md) / [manifest](../modules/manifest.md) / FrequencyOptions
+
+# Interface: FrequencyOptions<>
+
+[manifest](../modules/manifest.md).FrequencyOptions
+
+frequency options object
+
+## Properties
+
+### dayOfMonth
+
+• **dayOfMonth**: `number`
+
+day of the month
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:329](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L329)
+
+***
+
+### dayOfWeek
+
+• **dayOfWeek**: `number`
+
+day of the week
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:330](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L330)
+
+***
+
+### hours
+
+• **hours**: `number`
+
+hours
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:331](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L331)
+
+***
+
+### minutes
+
+• **minutes**: `number`
+
+minutes
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:332](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L332)
diff --git a/docs/api/cozy-client/interfaces/manifest.randomDayTimeResult.md b/docs/api/cozy-client/interfaces/manifest.randomDayTimeResult.md
new file mode 100644
index 0000000000..f225830490
--- /dev/null
+++ b/docs/api/cozy-client/interfaces/manifest.randomDayTimeResult.md
@@ -0,0 +1,29 @@
+[cozy-client](../README.md) / [manifest](../modules/manifest.md) / randomDayTimeResult
+
+# Interface: randomDayTimeResult<>
+
+[manifest](../modules/manifest.md).randomDayTimeResult
+
+## Properties
+
+### hours
+
+• **hours**: `number`
+
+hours
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:323](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L323)
+
+***
+
+### minutes
+
+• **minutes**: `number`
+
+minutes
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:324](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L324)
diff --git a/docs/api/cozy-client/modules/manifest.md b/docs/api/cozy-client/modules/manifest.md
index 9d3cb90c13..75f8b5a450 100644
--- a/docs/api/cozy-client/modules/manifest.md
+++ b/docs/api/cozy-client/modules/manifest.md
@@ -2,6 +2,11 @@
 
 # Namespace: manifest
 
+## Interfaces
+
+*   [FrequencyOptions](../interfaces/manifest.FrequencyOptions.md)
+*   [randomDayTimeResult](../interfaces/manifest.randomDayTimeResult.md)
+
 ## Variables
 
 ### ROLE_IDENTIFIER
@@ -22,7 +27,7 @@ Legacy login fields declared by some konnectors
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:11](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L11)
+[packages/cozy-client/src/models/manifest.js:21](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L21)
 
 ## Functions
 
@@ -42,7 +47,59 @@ Legacy login fields declared by some konnectors
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:63](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L63)
+[packages/cozy-client/src/models/manifest.js:73](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L73)
+
+***
+
+### getCronFromFrequency
+
+▸ **getCronFromFrequency**(`frequency`, `options?`): `string`
+
+Build a cron string for given frequency with given options
+See https://docs.cozy.io/en/cozy-stack/jobs/#cron-syntax
+
+*Parameters*
+
+| Name | Type | Description |
+| :------ | :------ | :------ |
+| `frequency` | `"hourly"` | `"daily"` | `"weekly"` | `"monthly"` | Frequency |
+| `options` | [`FrequencyOptions`](../interfaces/manifest.FrequencyOptions.md) | - |
+
+*Returns*
+
+`string`
+
+*   The cron definition for trigger
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:280](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L280)
+
+***
+
+### getCronFromKonnector
+
+▸ **getCronFromKonnector**(`konnector`, `startDate?`, `randomDayTimeFn?`): `string`
+
+Build a cron string for given konnector and from a given start date
+
+*Parameters*
+
+| Name | Type | Default value | Description |
+| :------ | :------ | :------ | :------ |
+| `konnector` | `IOCozyKonnector` | `undefined` | io.cozy.konnectors object |
+| `startDate` | `Date` | `undefined` | start date |
+| `randomDayTimeFn` | `Function` | `randomDayTime` | - |
+
+*Returns*
+
+`string`
+
+*   The cron definition for trigger
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:307](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L307)
 
 ***
 
@@ -66,7 +123,7 @@ The key for the identifier field, example 'login'
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:161](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L161)
+[packages/cozy-client/src/models/manifest.js:171](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L171)
 
 ***
 
@@ -86,7 +143,33 @@ The key for the identifier field, example 'login'
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:67](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L67)
+[packages/cozy-client/src/models/manifest.js:77](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L77)
+
+***
+
+### randomDayTime
+
+▸ **randomDayTime**(`start?`, `end?`, `randomize?`): [`randomDayTimeResult`](../interfaces/manifest.randomDayTimeResult.md)
+
+Returns an hour of the day between two hours given in parameters
+
+*Parameters*
+
+| Name | Type | Default value | Description |
+| :------ | :------ | :------ | :------ |
+| `start` | `number` | `0` | minimal start hour |
+| `end` | `number` | `1` | maximal end hour |
+| `randomize` | `Function` | `undefined` | The function used to generate random values |
+
+*Returns*
+
+[`randomDayTimeResult`](../interfaces/manifest.randomDayTimeResult.md)
+
+Object containing two atributes : hours and minutes
+
+*Defined in*
+
+[packages/cozy-client/src/models/manifest.js:248](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L248)
 
 ***
 
@@ -108,7 +191,7 @@ Normalize app manifest, retro-compatibility for old manifests
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:77](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L77)
+[packages/cozy-client/src/models/manifest.js:87](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L87)
 
 ***
 
@@ -132,7 +215,7 @@ sanitized categories
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:56](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L56)
+[packages/cozy-client/src/models/manifest.js:66](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L66)
 
 ***
 
@@ -156,4 +239,4 @@ Ensures that fields has at least one field with the role 'identifier'
 
 *Defined in*
 
-[packages/cozy-client/src/models/manifest.js:130](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L130)
+[packages/cozy-client/src/models/manifest.js:140](https://github.com/cozy/cozy-client/blob/master/packages/cozy-client/src/models/manifest.js#L140)
diff --git a/packages/cozy-client/src/models/manifest.js b/packages/cozy-client/src/models/manifest.js
index ee454b12d2..4cc508ceaf 100644
--- a/packages/cozy-client/src/models/manifest.js
+++ b/packages/cozy-client/src/models/manifest.js
@@ -5,6 +5,16 @@ import findKey from 'lodash/findKey'
 
 export const ROLE_IDENTIFIER = 'identifier'
 
+const DAILY = 'daily'
+const HOURLY = 'hourly'
+const WEEKLY = 'weekly'
+const MONTHLY = 'monthly'
+const VALID_FREQUENCIES = [DAILY, HOURLY, WEEKLY, MONTHLY]
+
+const DEFAULT_FREQUENCY = WEEKLY
+// By default konnectors are run at random hour between 12:00PM and 05:00AM.
+const DEFAULT_TIME_INTERVAL = [0, 5]
+
 /**
  * Legacy login fields declared by some konnectors
  */
@@ -226,3 +236,98 @@ const sanitizeFields = _flow([
   sanitizeRequired,
   sanitizeEncrypted
 ])
+
+/**
+ * Returns an hour of the day between two hours given in parameters
+ *
+ * @param {number} start minimal start hour
+ * @param {number} end maximal end hour
+ * @param {function} randomize The function used to generate random values
+ * @returns {randomDayTimeResult} Object containing two atributes : hours and minutes
+ */
+export const randomDayTime = (
+  start = 0,
+  end = 1,
+  randomize = (min, max) => Math.random() * (max - min) + min
+) => {
+  if (typeof start !== 'number')
+    throw new Error('Parameter start must be a number')
+  if (typeof end !== 'number') throw new Error('Parameter end must be a number')
+
+  if (typeof randomize !== 'function')
+    throw new Error('Parameter randomize must be a function')
+
+  if (start < 0 || end > 24) throw new Error('interval must be inside [0, 24]')
+
+  const r = randomize(start, end)
+  const hours = Math.floor(r)
+  const minutes = Math.floor((r - hours) * 60)
+
+  if (hours < 0 || hours > 23)
+    throw new Error('randomize function returns invalid hour value')
+
+  return { hours, minutes }
+}
+
+/**
+ * Build a cron string for given frequency with given options
+ * See https://docs.cozy.io/en/cozy-stack/jobs/#cron-syntax
+ *
+ * @param  {'hourly'|'daily'|'weekly'|'monthly'} frequency Frequency
+ * @param  {FrequencyOptions} [options] - FrequencyOptions object
+ * @returns {String} - The cron definition for trigger
+ */
+export const getCronFromFrequency = (frequency, options = {}) => {
+  const { dayOfMonth = 1, dayOfWeek = 1, hours = 0, minutes = 0 } = options
+  const sanitizedFrequency = VALID_FREQUENCIES.includes(frequency)
+    ? frequency
+    : DEFAULT_FREQUENCY
+
+  switch (sanitizedFrequency) {
+    case DAILY:
+      return `0 ${minutes} ${hours} * * *`
+    case HOURLY:
+      return `0 ${minutes} * * * *`
+    case MONTHLY:
+      return `0 ${minutes} ${hours} ${dayOfMonth} * *`
+    default:
+      // also WEEKLY
+      return `0 ${minutes} ${hours} * * ${dayOfWeek}`
+  }
+}
+
+/**
+ * Build a cron string for given konnector and from a given start date
+ *
+ * @param {import('../types').IOCozyKonnector} konnector - io.cozy.konnectors object
+ * @param {Date} startDate - start date
+ * @param {function} [randomDayTimeFn] - function generating random hours and minutes
+ * @returns {String} - The cron definition for trigger
+ */
+export const getCronFromKonnector = (
+  konnector,
+  startDate = new Date(),
+  randomDayTimeFn = randomDayTime
+) =>
+  getCronFromFrequency(konnector.frequency, {
+    ...randomDayTimeFn.apply(
+      null,
+      konnector.time_interval || DEFAULT_TIME_INTERVAL
+    ),
+    dayOfWeek: startDate.getDay(),
+    dayOfMonth: startDate.getDate()
+  })
+
+/**
+ * @typedef {object} randomDayTimeResult
+ * @property {number} hours - hours
+ * @property {number} minutes - minutes
+ */
+
+/**
+ * @typedef {object} FrequencyOptions - frequency options object
+ * @property {Number} [dayOfMonth] - day of the month
+ * @property {Number} [dayOfWeek] - day of the week
+ * @property {Number} [hours] - hours
+ * @property {Number} [minutes] - minutes
+ */
diff --git a/packages/cozy-client/src/models/manifest.spec.js b/packages/cozy-client/src/models/manifest.spec.js
index 5947c40275..cf29aa91eb 100644
--- a/packages/cozy-client/src/models/manifest.spec.js
+++ b/packages/cozy-client/src/models/manifest.spec.js
@@ -1,7 +1,10 @@
 import {
   sanitizeCategories,
   sanitize as sanitizeManifest,
-  getIdentifier
+  getIdentifier,
+  getCronFromFrequency,
+  getCronFromKonnector,
+  randomDayTime
 } from './manifest'
 
 describe('sanitizeCategories', () => {
@@ -444,3 +447,136 @@ describe('getIdentifier', () => {
     expect(getIdentifier({})).toBe(null)
   })
 })
+
+describe('getCronFromFrequency', () => {
+  const options = { dayOfMonth: 25, dayOfWeek: 4, hours: 14, minutes: 15 }
+  it('creates default cron (weekly)', () => {
+    expect(getCronFromFrequency()).toEqual('0 0 0 * * 1')
+  })
+  it('creates weekly cron', () => {
+    expect(getCronFromFrequency('weekly', options)).toEqual('0 15 14 * * 4')
+  })
+  it('creates monthly cron', () => {
+    expect(getCronFromFrequency('monthly', options)).toEqual('0 15 14 25 * *')
+  })
+  it('creates daily cron', () => {
+    expect(getCronFromFrequency('daily', options)).toEqual('0 15 14 * * *')
+  })
+  it('creates hourly cron', () => {
+    expect(getCronFromFrequency('hourly', options)).toEqual('0 15 * * * *')
+  })
+})
+
+describe('getCronFromKonnector', () => {
+  const randomDayTimeMock = jest.fn()
+
+  beforeEach(() => {
+    randomDayTimeMock.mockImplementation((min, max) => ({
+      hours: max - 1,
+      minutes: 59
+    }))
+  })
+  afterEach(() => {
+    randomDayTimeMock.mockReset()
+  })
+  it('returns expected default cron', () => {
+    const konnector = {}
+    const date = new Date('2019-02-07T14:12:00')
+    expect(getCronFromKonnector(konnector, date, randomDayTimeMock)).toEqual(
+      `0 59 4 * * 4`
+    )
+  })
+  it('returns expected monthly cron', () => {
+    const konnector = {
+      frequency: 'monthly'
+    }
+    const date = new Date('2019-02-07T14:12:00')
+    expect(getCronFromKonnector(konnector, date, randomDayTimeMock)).toEqual(
+      `0 59 4 7 * *`
+    )
+  })
+  it('returns expected cron with time interval', () => {
+    const konnector = {
+      time_interval: [0, 12]
+    }
+    const date = new Date('2019-02-07T14:12:00')
+    expect(getCronFromKonnector(konnector, date, randomDayTimeMock)).toEqual(
+      `0 59 11 * * 4`
+    )
+  })
+})
+
+describe('daytime library', () => {
+  describe('randomDayTime', () => {
+    it('throws error on inconsistent start hour', () => {
+      expect(() => randomDayTime(-1, 12)).toThrow(
+        'interval must be inside [0, 24]'
+      )
+    })
+    it('throws error on inconsistent end hour', () => {
+      expect(() => randomDayTime(2, 26)).toThrow(
+        'interval must be inside [0, 24]'
+      )
+    })
+    it('throws error when randomize is null', () => {
+      expect(() => randomDayTime(0, 1, null)).toThrow(
+        'Parameter randomize must be a function'
+      )
+    })
+    it('throws error when randomize is not a function', () => {
+      expect(() => randomDayTime(0, 1, 2)).toThrow(
+        'Parameter randomize must be a function'
+      )
+    })
+    it('returns expected hours/minutes values', () => {
+      const randomizeStub = jest.fn().mockReturnValueOnce(10.58)
+
+      const result = randomDayTime(0, 24, randomizeStub)
+
+      expect(result).toEqual({
+        hours: 10,
+        minutes: 34
+      })
+    })
+    it('returns defaut hours/minutes with no parameter', () => {
+      // Test based on random function, not sure if it is a good idea, but it
+      // makes code 100% covered.
+      const result = randomDayTime()
+
+      expect(result.hours).toBe(0)
+
+      expect(result.minutes).toBeGreaterThanOrEqual(0)
+      expect(result.minutes).toBeLessThanOrEqual(59)
+    })
+    it('returns valid hours/minutes with default randomize function', () => {
+      // Test based on random function, not sure if it is a good idea, but it
+      // makes code 100% covered.
+      const result = randomDayTime(19, 21)
+
+      expect(result.hours).toBeGreaterThanOrEqual(19)
+      expect(result.hours).toBeLessThanOrEqual(20)
+
+      expect(result.minutes).toBeGreaterThanOrEqual(0)
+      expect(result.minutes).toBeLessThanOrEqual(59)
+    })
+    it('throw error on incorrect minimal hour', () => {
+      const randomizeStub = jest.fn().mockReturnValueOnce(-1)
+
+      expect(() => randomDayTime(0, 24, randomizeStub)).toThrow(
+        'randomize function returns invalid hour value'
+      )
+    })
+    it('throws error on incorrect maximal hour', () => {
+      const randomizeStub = jest.fn().mockReturnValueOnce(24)
+
+      expect(() => randomDayTime(0, 24, randomizeStub)).toThrow(
+        'randomize function returns invalid hour value'
+      )
+    })
+    it('handles floats', () => {
+      const randomizeStub = jest.fn().mockReturnValueOnce(10.58)
+      randomDayTime(5.5, 6.5, randomizeStub)
+      expect(randomizeStub).toHaveBeenCalledWith(5.5, 6.5)
+    })
+  })
+})
diff --git a/packages/cozy-client/src/types.js b/packages/cozy-client/src/types.js
index 971ee98755..9310d7ff39 100644
--- a/packages/cozy-client/src/types.js
+++ b/packages/cozy-client/src/types.js
@@ -33,6 +33,8 @@ import { QueryDefinition } from './queries/dsl'
  * @property {String} slug - slug of konnector
  * @property {ManifestFields} fields - konnector fields
  * @property {Boolean} clientSide - whether the konnector runs on client or not
+ * @property {'hourly'|'daily'|'weekly'|'monthly'} frequency - frequency at which the konnector is supposed to be run
+ * @property {Array<number>} time_interval - interval of hours in the day where the konnector can be run
  * @typedef {CozyClientDocument & KonnectorsDocument} IOCozyKonnector - An io.cozy.konnectors document
  */
 
diff --git a/packages/cozy-client/types/models/manifest.d.ts b/packages/cozy-client/types/models/manifest.d.ts
index 003a864753..564aee3e18 100644
--- a/packages/cozy-client/types/models/manifest.d.ts
+++ b/packages/cozy-client/types/models/manifest.d.ts
@@ -21,3 +21,37 @@ export const ROLE_IDENTIFIER: "identifier";
 export const legacyLoginFields: string[];
 export function sanitizeIdentifier(fields: import('../types').ManifestFields): import('../types').ManifestFields;
 export function getIdentifier(fields?: import('../types').ManifestFields): string | null;
+export function randomDayTime(start?: number, end?: number, randomize?: Function): randomDayTimeResult;
+export function getCronFromFrequency(frequency: 'hourly' | 'daily' | 'weekly' | 'monthly', options?: FrequencyOptions): string;
+export function getCronFromKonnector(konnector: import('../types').IOCozyKonnector, startDate?: Date, randomDayTimeFn?: Function): string;
+export type randomDayTimeResult = {
+    /**
+     * - hours
+     */
+    hours: number;
+    /**
+     * - minutes
+     */
+    minutes: number;
+};
+/**
+ * - frequency options object
+ */
+export type FrequencyOptions = {
+    /**
+     * - day of the month
+     */
+    dayOfMonth?: number;
+    /**
+     * - day of the week
+     */
+    dayOfWeek?: number;
+    /**
+     * - hours
+     */
+    hours?: number;
+    /**
+     * - minutes
+     */
+    minutes?: number;
+};
diff --git a/packages/cozy-client/types/types.d.ts b/packages/cozy-client/types/types.d.ts
index 12aabd77ed..1d52af22c2 100644
--- a/packages/cozy-client/types/types.d.ts
+++ b/packages/cozy-client/types/types.d.ts
@@ -54,6 +54,14 @@ export type KonnectorsDocument = {
      * - whether the konnector runs on client or not
      */
     clientSide: boolean;
+    /**
+     * - frequency at which the konnector is supposed to be run
+     */
+    frequency: 'hourly' | 'daily' | 'weekly' | 'monthly';
+    /**
+     * - interval of hours in the day where the konnector can be run
+     */
+    time_interval: Array<number>;
 };
 /**
  * - An io.cozy.konnectors document