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Expo Calendar

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A library that provides an API for interacting with the device's system calendars, events, reminders, and associated records.

expo-calendar provides an API for interacting with the device's system calendars, events, reminders, and associated records.

Platform Compatibility

Android Device	Android Emulator	iOS Device	iOS Simulator	Web

Installation

Terminal

- npx expo install expo-calendar

If you're installing this in a bare React Native app, you should also follow these additional installation instructions.

Configuration in app.json/app.config.js

You can configure expo-calendar using its built-in config plugin if you use config plugins in your project (EAS Build or npx expo run:[android|ios]). The plugin allows you to configure various properties that cannot be set at runtime and require building a new app binary to take effect.

Example app.json with config plugin

app.json

{
  "expo": {
    "plugins": [
      [
        "expo-calendar",
        {
          "calendarPermission": "The app needs to access your calendar."
        }
      ]
    ]
  }
}

Configurable properties

Name	Default	Description
`calendarPermission`	`"Allow $(PRODUCT_NAME) to access your calendar"`	Only for: iOS A string to set the `NSCalendarsUsageDescription` permission message.
`remindersPermission`	`"Allow $(PRODUCT_NAME) to access your reminders"`	Only for: iOS A string to set the `NSRemindersUsageDescription` permission message.

Are you using this library in a bare React Native app?

Learn how to configure the native projects in the installation instructions in the expo-calendar repository.

Usage

Basic Calendar usage

import React, { useEffect } from 'react';
import { StyleSheet, View, Text, Button, Platform } from 'react-native';
import * as Calendar from 'expo-calendar';

export default function App() {
  useEffect(() => {
    (async () => {
      const { status } = await Calendar.requestCalendarPermissionsAsync();
      if (status === 'granted') {
        const calendars = await Calendar.getCalendarsAsync(Calendar.EntityTypes.EVENT);
        console.log('Here are all your calendars:');
        console.log({ calendars });
      }
    })();
  }, []);

  return (
    <View style={styles.container}>
      <Text>Calendar Module Example</Text>
      <Button title="Create a new calendar" onPress={createCalendar} />
    </View>
  );
}

async function getDefaultCalendarSource() {
  const defaultCalendar = await Calendar.getDefaultCalendarAsync();
  return defaultCalendar.source;
}

async function createCalendar() {
  const defaultCalendarSource =
    Platform.OS === 'ios'
      ? await getDefaultCalendarSource()
      : { isLocalAccount: true, name: 'Expo Calendar' };
  const newCalendarID = await Calendar.createCalendarAsync({
    title: 'Expo Calendar',
    color: 'blue',
    entityType: Calendar.EntityTypes.EVENT,
    sourceId: defaultCalendarSource.id,
    source: defaultCalendarSource,
    name: 'internalCalendarName',
    ownerAccount: 'personal',
    accessLevel: Calendar.CalendarAccessLevel.OWNER,
  });
  console.log(`Your new calendar ID is: ${newCalendarID}`);
}

%%placeholder-start%%const styles = StyleSheet.create({ ... }); %%placeholder-end%%const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'space-around',
  },
});

API

import * as Calendar from 'expo-calendar';

Constants

`Calendar.AlarmMethod`

Type: { ALARM: string, ALERT: string, DEFAULT: string, EMAIL: string, SMS: string }

`Calendar.AttendeeRole`

Type: { ATTENDEE: string, CHAIR: string, NONE: string, NON_PARTICIPANT: string, OPTIONAL: string, ORGANIZER: string, PERFORMER: string, REQUIRED: string, SPEAKER: string, UNKNOWN: string }

`Calendar.AttendeeStatus`

Type: { ACCEPTED: string, COMPLETED: string, DECLINED: string, DELEGATED: string, INVITED: string, IN_PROCESS: string, NONE: string, PENDING: string, TENTATIVE: string, UNKNOWN: string }

`Calendar.AttendeeType`

Type: { GROUP: string, NONE: string, OPTIONAL: string, PERSON: string, REQUIRED: string, RESOURCE: string, ROOM: string, UNKNOWN: string }

`Calendar.Availability`

Type: { BUSY: string, FREE: string, NOT_SUPPORTED: string, TENTATIVE: string, UNAVAILABLE: string }

`Calendar.CalendarAccessLevel`

Type: { CONTRIBUTOR: string, EDITOR: string, FREEBUSY: string, NONE: string, OVERRIDE: string, OWNER: string, READ: string, RESPOND: string, ROOT: string }

`Calendar.CalendarType`

Type: { BIRTHDAYS: string, CALDAV: string, EXCHANGE: string, LOCAL: string, SUBSCRIBED: string, UNKNOWN: string }

`Calendar.EntityTypes`

Type: { EVENT: string, REMINDER: string }

`Calendar.EventAccessLevel`

Type: { CONFIDENTIAL: string, DEFAULT: string, PRIVATE: string, PUBLIC: string }

`Calendar.EventStatus`

Type: { CANCELED: string, CONFIRMED: string, NONE: string, TENTATIVE: string }

`Calendar.Frequency`

Type: { DAILY: string, MONTHLY: string, WEEKLY: string, YEARLY: string }

`Calendar.ReminderStatus`

Type: { COMPLETED: string, INCOMPLETE: string }

`Calendar.SourceType`

Type: { BIRTHDAYS: string, CALDAV: string, EXCHANGE: string, LOCAL: string, MOBILEME: string, SUBSCRIBED: string }

Hooks

`useCalendarPermissions(options)`

Name	Type	Description
options (optional)	`PermissionHookOptions<object>`	-

Check or request permissions to access the calendar. This uses both getCalendarPermissionsAsync and requestCalendarPermissionsAsync to interact with the permissions.

Example

const [status, requestPermission] = Calendar.useCalendarPermissions();

Returns

[null | PermissionResponse, RequestPermissionMethod<PermissionResponse>, GetPermissionMethod<PermissionResponse>]

`useRemindersPermissions(options)`

Name	Type	Description
options (optional)	`PermissionHookOptions<object>`	-

Check or request permissions to access reminders. This uses both getRemindersPermissionsAsync and requestRemindersPermissionsAsync to interact with the permissions.

Example

const [status, requestPermission] = Calendar.useRemindersPermissions();

Returns

[null | PermissionResponse, RequestPermissionMethod<PermissionResponse>, GetPermissionMethod<PermissionResponse>]

Methods

Only for:

Android

`Calendar.createAttendeeAsync(eventId, details)`

Name	Type	Description
eventId	`string`	ID of the event to add this attendee to.
details (optional)	`Partial<Attendee>`	A map of details for the attendee to be created. Default: `{}`

Creates a new attendee record and adds it to the specified event. Note that if eventId specifies a recurring event, this will add the attendee to every instance of the event.

Returns

Promise<string>

A string representing the ID of the newly created attendee record.

`Calendar.createCalendarAsync(details)`

Name	Type	Description
details (optional)	`Partial<Calendar>`	A map of details for the calendar to be created. Default: `{}`

Creates a new calendar on the device, allowing events to be added later and displayed in the OS Calendar app.

Returns

Promise<string>

A string representing the ID of the newly created calendar.

`Calendar.createEventAsync(calendarId, eventData)`

Name	Type	Description
calendarId	`string`	ID of the calendar to create this event in.
eventData (optional)	`Partial<Event>`	A map of details for the event to be created. Default: `{}`

Creates a new event on the specified calendar.

Returns

Promise<string>

A promise which fulfils with a string representing the ID of the newly created event.

Only for:

iOS

`Calendar.createReminderAsync(calendarId, reminder)`

Name	Type	Description
calendarId	`null \| string`	ID of the calendar to create this reminder in (or `null` to add the calendar to the OS-specified default calendar for reminders).
reminder (optional)	`Reminder`	A map of details for the reminder to be created Default: `{}`

Creates a new reminder on the specified calendar.

Returns

Promise<string>

A promise which fulfils with a string representing the ID of the newly created reminder.

Only for:

Android

`Calendar.deleteAttendeeAsync(id)`

Name	Type	Description
id	`string`	ID of the attendee to delete.

Deletes an existing attendee record from the device. Use with caution.

Returns

Promise<void>

`Calendar.deleteCalendarAsync(id)`

Name	Type	Description
id	`string`	ID of the calendar to delete.

Deletes an existing calendar and all associated events/reminders/attendees from the device. Use with caution.

Returns

Promise<void>

`Calendar.deleteEventAsync(id, recurringEventOptions)`

Name	Type	Description
id	`string`	ID of the event to be deleted.
recurringEventOptions (optional)	`RecurringEventOptions`	A map of options for recurring events. Default: `{}`

Deletes an existing event from the device. Use with caution.

Returns

Promise<void>

Only for:

iOS

`Calendar.deleteReminderAsync(id)`

Name	Type	Description
id	`string`	ID of the reminder to be deleted.

Deletes an existing reminder from the device. Use with caution.

Returns

Promise<void>

`Calendar.getAttendeesForEventAsync(id, recurringEventOptions)`

Name	Type	Description
id	`string`	ID of the event to return attendees for.
recurringEventOptions (optional)	`RecurringEventOptions`	A map of options for recurring events. Default: `{}`

Gets all attendees for a given event (or instance of a recurring event).

Returns

Promise<Attendee[]>

A promise which fulfils with an array of Attendee associated with the specified event.

`Calendar.getCalendarPermissionsAsync()`

Checks user's permissions for accessing user's calendars.

Returns

Promise<PermissionResponse>

A promise that resolves to an object of type PermissionResponse.

`Calendar.getCalendarsAsync(entityType)`

Name Type Description

Name	Type	Description
entityType (optional)	`string`	iOS Only. Not required, but if defined, filters the returned calendars to a specific entity type. Possible values are `Calendar.EntityTypes.EVENT` (for calendars shown in the Calendar app) and `Calendar.EntityTypes.REMINDER` (for the Reminders app). Note: If not defined, you will need both permissions: CALENDAR and REMINDERS.

entityType
(optional)

string

iOS Only. Not required, but if defined, filters the returned calendars to a specific entity type. Possible values are Calendar.EntityTypes.EVENT (for calendars shown in the Calendar app) and Calendar.EntityTypes.REMINDER (for the Reminders app).

Note: If not defined, you will need both permissions: CALENDAR and REMINDERS.

Gets an array of calendar objects with details about the different calendars stored on the device.

Returns

Promise<Calendar[]>

An array of calendar objects matching the provided entity type (if provided).

Only for:

iOS

`Calendar.getDefaultCalendarAsync()`

Gets an instance of the default calendar object.

Returns

Promise<Calendar>

A promise resolving to the Calendar object that is the user's default calendar.

`Calendar.getEventAsync(id, recurringEventOptions)`

Name	Type	Description
id	`string`	ID of the event to return.
recurringEventOptions (optional)	`RecurringEventOptions`	A map of options for recurring events. Default: `{}`

Returns a specific event selected by ID. If a specific instance of a recurring event is desired, the start date of this instance must also be provided, as instances of recurring events do not have their own unique and stable IDs on either iOS or Android.

Returns

Promise<Event>

A promise which fulfils with an Event object matching the provided criteria, if one exists.

`Calendar.getEventsAsync(calendarIds, startDate, endDate)`

Name	Type	Description
calendarIds	`string[]`	Array of IDs of calendars to search for events in.
startDate	`Date`	Beginning of time period to search for events in.
endDate	`Date`	End of time period to search for events in.

Returns all events in a given set of calendars over a specified time period. The filtering has slightly different behavior per-platform - on iOS, all events that overlap at all with the [startDate, endDate] interval are returned, whereas on Android, only events that begin on or after the startDate and end on or before the endDate will be returned.

Returns

Promise<Event[]>

A promise which fulfils with an array of Event objects matching the search criteria.

Only for:

iOS

`Calendar.getReminderAsync(id)`

Name	Type	Description
id	`string`	ID of the reminder to return.

Returns a specific reminder selected by ID.

Returns

Promise<Reminder>

A promise which fulfils with a Reminder matching the provided ID, if one exists.

Only for:

iOS

`Calendar.getRemindersAsync(calendarIds, status, startDate, endDate)`

Name	Type	Description
calendarIds	`(null \| string)[]`	Array of IDs of calendars to search for reminders in.
status	`null \| string`	One of `Calendar.ReminderStatus.COMPLETED` or `Calendar.ReminderStatus.INCOMPLETE`.
startDate	`Date`	Beginning of time period to search for reminders in. Required if `status` is defined.
endDate	`Date`	End of time period to search for reminders in. Required if `status` is defined.

Returns a list of reminders matching the provided criteria. If startDate and endDate are defined, returns all reminders that overlap at all with the [startDate, endDate] interval - i.e. all reminders that end after the startDate or begin before the endDate.

Returns

Promise<Reminder[]>

A promise which fulfils with an array of Reminder objects matching the search criteria.

Only for:

iOS

`Calendar.getRemindersPermissionsAsync()`

Checks user's permissions for accessing user's reminders.

Returns

Promise<PermissionResponse>

A promise that resolves to an object of type PermissionResponse.

Only for:

iOS

`Calendar.getSourceAsync(id)`

Name	Type	Description
id	`string`	ID of the source to return.

Returns a specific source selected by ID.

Returns

Promise<Source>

A promise which fulfils with an array of Source object matching the provided ID, if one exists.

Only for:

iOS

`Calendar.getSourcesAsync()`

Returns

Promise<Source[]>

A promise which fulfils with an array of Source objects all sources for calendars stored on the device.

`Calendar.isAvailableAsync()`

Returns whether the Calendar API is enabled on the current device. This does not check the app permissions.

Returns

Promise<boolean>

Async boolean, indicating whether the Calendar API is available on the current device. Currently, this resolves true on iOS and Android only.

Only for:

Android

`Calendar.openEventInCalendar(id)`

Name	Type	Description
id	`string`	ID of the event to open.

Sends an intent to open the specified event in the OS Calendar app.

Returns

void

`Calendar.requestCalendarPermissionsAsync()`

Asks the user to grant permissions for accessing user's calendars.

Returns

Promise<PermissionResponse>

A promise that resolves to an object of type PermissionResponse.

Deprecated. Use requestCalendarPermissionsAsync() instead.

`Calendar.requestPermissionsAsync()`

Returns

Promise<PermissionResponse>

Only for:

iOS

`Calendar.requestRemindersPermissionsAsync()`

Asks the user to grant permissions for accessing user's reminders.

Returns

Promise<PermissionResponse>

A promise that resolves to an object of type PermissionResponse.

Only for:

Android

`Calendar.updateAttendeeAsync(id, details)`

Name	Type	Description
id	`string`	ID of the attendee record to be updated.
details (optional)	`Partial<Attendee>`	A map of properties to be updated. Default: `{}`

Updates an existing attendee record. To remove a property, explicitly set it to null in details.

Returns

Promise<string>

`Calendar.updateCalendarAsync(id, details)`

Name	Type	Description
id	`string`	ID of the calendar to update.
details (optional)	`Partial<Calendar>`	A map of properties to be updated. Default: `{}`

Updates the provided details of an existing calendar stored on the device. To remove a property, explicitly set it to null in details.

Returns

Promise<string>

`Calendar.updateEventAsync(id, details, recurringEventOptions)`

Name	Type	Description
id	`string`	ID of the event to be updated.
details (optional)	`Partial<Event>`	A map of properties to be updated. Default: `{}`
recurringEventOptions (optional)	`RecurringEventOptions`	A map of options for recurring events. Default: `{}`

Updates the provided details of an existing calendar stored on the device. To remove a property, explicitly set it to null in details.

Returns

Promise<string>

Only for:

iOS

`Calendar.updateReminderAsync(id, details)`

Name	Type	Description
id	`string`	ID of the reminder to be updated.
details (optional)	`Reminder`	A map of properties to be updated. Default: `{}`

Updates the provided details of an existing reminder stored on the device. To remove a property, explicitly set it to null in details.

Returns

Promise<string>

Interfaces

`PermissionResponse`

An object obtained by permissions get and request functions.

PermissionResponse Properties

Name	Type	Description
canAskAgain	`boolean`	Indicates if user can be asked again for specific permission. If not, one should be directed to the Settings app in order to enable/disable the permission.
expires	`PermissionExpiration`	Determines time when the permission expires.
granted	`boolean`	A convenience boolean that indicates if the permission is granted.
status	`PermissionStatus`	Determines the status of the permission.

Types

`Alarm`

A method for having the OS automatically remind the user about an calendar item.

Name	Type	Description
absoluteDate (optional)	`string`	Only for: iOS Date object or string representing an absolute time the alarm should occur. Overrides `relativeOffset` and `structuredLocation` if specified alongside either.
method (optional)	`string`	Only for: Android Method of alerting the user that this alarm should use; on iOS this is always a notification. Possible values: `AlarmMethod`.
relativeOffset (optional)	`number`	Number of minutes from the `startDate` of the calendar item that the alarm should occur. Use negative values to have the alarm occur before the `startDate`.
structuredLocation (optional)	`AlarmLocation`	-

`AlarmLocation`

Name	Type	Description
coords (optional)	`{ latitude: number, longitude: number }`	-
proximity (optional)	`string`	-
radius (optional)	`number`	-
title (optional)	`string`	-

`Attendee`

A person or entity that is associated with an event by being invited or fulfilling some other role.

Name	Type	Description
email (optional)	`string`	Only for: Android Email address of the attendee.
id (optional)	`string`	Only for: Android Internal ID that represents this attendee on the device.
isCurrentUser (optional)	`boolean`	Only for: iOS Indicates whether or not this attendee is the current OS user.
name	`string`	Displayed name of the attendee.
role	`string`	Role of the attendee at the event. Possible values: `AttendeeRole`.
status	`string`	Status of the attendee in relation to the event. Possible values: `AttendeeStatus`.
type	`string`	Type of the attendee. Possible values: `AttendeeType`.
url (optional)	`string`	Only for: iOS URL for the attendee.

`Calendar`

A calendar record upon which events (or, on iOS, reminders) can be stored. Settings here apply to the calendar as a whole and how its events are displayed in the OS calendar app.

Name	Type	Description
accessLevel (optional)	`string`	Only for: Android Level of access that the user has for the calendar. Possible values: `CalendarAccessLevel`.
allowedAttendeeTypes (optional)	`string[]`	Only for: Android Attendee types that this calendar supports. Possible values: Array of `AttendeeType`.
allowedAvailabilities	`string[]`	Availability types that this calendar supports. Possible values: Array of `Availability`.
allowedReminders (optional)	`string[]`	Only for: Android Alarm methods that this calendar supports. Possible values: Array of `AlarmMethod`.
allowsModifications	`boolean`	Boolean value that determines whether this calendar can be modified.
color	`string`	Color used to display this calendar's events.
entityType (optional)	`string`	Only for: iOS Whether the calendar is used in the Calendar or Reminders OS app. Possible values: `EntityTypes`.
id	`string`	Internal ID that represents this calendar on the device.
isPrimary (optional)	`boolean`	Only for: Android Boolean value indicating whether this is the device's primary calendar.
isSynced (optional)	`boolean`	Only for: Android Indicates whether this calendar is synced and its events stored on the device. Unexpected behavior may occur if this is not set to `true`.
isVisible (optional)	`boolean`	Only for: Android Indicates whether the OS displays events on this calendar.
name (optional)	`string \| null`	Only for: Android Internal system name of the calendar.
ownerAccount (optional)	`string`	Only for: Android Name for the account that owns this calendar.
source	`Source`	Object representing the source to be used for the calendar.
sourceId (optional)	`string`	Only for: iOS ID of the source to be used for the calendar. Likely the same as the source for any other locally stored calendars.
timeZone (optional)	`string`	Only for: Android Time zone for the calendar.
title	`string`	Visible name of the calendar.
type (optional)	`string`	Only for: iOS Type of calendar this object represents. Possible values: `CalendarType`.

Only for:

iOS

`DaysOfTheWeek`

Name	Type	Description
dayOfTheWeek	`DayOfTheWeek`	Sunday to Saturday - `DayOfTheWeek` enum.
weekNumber (optional)	`number`	`-53` to `53` (`0` ignores this field, and a negative indicates a value from the end of the range).

`Event`

An event record, or a single instance of a recurring event. On iOS, used in the Calendar app.

Name	Type	Description
accessLevel (optional)	`string`	Only for: Android User's access level for the event. Possible values: `EventAccessLevel`.
alarms	`Alarm[]`	Array of Alarm objects which control automated reminders to the user.
allDay	`boolean`	Whether the event is displayed as an all-day event on the calendar
availability	`string`	The availability setting for the event. Possible values: `Availability`.
calendarId	`string`	ID of the calendar that contains this event.
creationDate (optional)	`string \| Date`	Only for: iOS Date when the event record was created.
endDate	`string \| Date`	Date object or string representing the time when the event ends.
endTimeZone (optional)	`string`	Only for: Android Time zone for the event end time.
guestsCanInviteOthers (optional)	`boolean`	Only for: Android Whether invited guests can invite other guests.
guestsCanModify (optional)	`boolean`	Only for: Android Whether invited guests can modify the details of the event.
guestsCanSeeGuests (optional)	`boolean`	Only for: Android Whether invited guests can see other guests.
id	`string`	Internal ID that represents this event on the device.
instanceId (optional)	`string`	Only for: Android For instances of recurring events, volatile ID representing this instance. Not guaranteed to always refer to the same instance.
isDetached (optional)	`boolean`	Only for: iOS Boolean value indicating whether or not the event is a detached (modified) instance of a recurring event.
lastModifiedDate (optional)	`string \| Date`	Only for: iOS Date when the event record was last modified.
location	`string`	Location field of the event.
notes	`string`	Description or notes saved with the event.
organizer (optional)	`string`	Only for: iOS Organizer of the event.
organizerEmail (optional)	`string`	Only for: Android Email address of the organizer of the event.
originalId (optional)	`string`	Only for: Android For detached (modified) instances of recurring events, the ID of the original recurring event.
originalStartDate (optional)	`string \| Date`	Only for: iOS For recurring events, the start date for the first (original) instance of the event.
recurrenceRule	`RecurrenceRule`	Object representing rules for recurring or repeating events. Set to `null` for one-time events.
startDate	`string \| Date`	Date object or string representing the time when the event starts.
status	`string`	Status of the event. Possible values: `EventStatus`.
timeZone	`string`	Time zone the event is scheduled in.
title	`string`	Visible name of the event.
url (optional)	`string`	Only for: iOS URL for the event.

`PermissionHookOptions`

Acceptable values are: PermissionHookBehavior, Options.

`RecurrenceRule`

A recurrence rule for events or reminders, allowing the same calendar item to recur multiple times. This type is based on the iOS interface which is in turn based on the iCal RFC so you can refer to those to learn more about this potentially complex interface.

Not all of the combinations make sense. For example, when frequency is DAILY, setting daysOfTheMonth makes no sense.

Name	Type	Description
daysOfTheMonth (optional)	`number[]`	Only for: iOS The days of the month this event occurs on. `-31` to `31` (not including `0`). Negative indicates a value from the end of the range. This field is only valid for `Calendar.Frequency.Monthly`.
daysOfTheWeek (optional)	`DaysOfTheWeek[]`	Only for: iOS The days of the week the event should recur on. An array of `DaysOfTheWeek` object.
daysOfTheYear (optional)	`number[]`	Only for: iOS The days of the year this event occurs on. `-366` to `366` (not including `0`). Negative indicates a value from the end of the range. This field is only valid for `Calendar.Frequency.Yearly`.
endDate (optional)	`string \| Date`	Date on which the calendar item should stop recurring; overrides `occurrence` if both are specified.
frequency	`string`	How often the calendar item should recur. Possible values: `Frequency`.
interval (optional)	`number`	Interval at which the calendar item should recur. For example, an `interval: 2` with `frequency: DAILY` would yield an event that recurs every other day. Default: `1`
monthsOfTheYear (optional)	`MonthOfTheYear[]`	Only for: iOS The months this event occurs on. This field is only valid for `Calendar.Frequency.Yearly`.
occurrence (optional)	`number`	Number of times the calendar item should recur before stopping.
setPositions (optional)	`number[]`	Only for: iOS TAn array of numbers that filters which recurrences to include. For example, for an event that recurs every Monday, passing 2 here will make it recur every other Monday. `-366` to `366` (not including `0`). Negative indicates a value from the end of the range. This field is only valid for `Calendar.Frequency.Yearly`.
weeksOfTheYear (optional)	`number[]`	Only for: iOS The weeks of the year this event occurs on. `-53` to `53` (not including `0`). Negative indicates a value from the end of the range. This field is only valid for `Calendar.Frequency.Yearly`.

Only for:

iOS

`RecurringEventOptions`

Name	Type	Description
futureEvents (optional)	`boolean`	Whether or not future events in the recurring series should also be updated. If `true`, will apply the given changes to the recurring instance specified by `instanceStartDate` and all future events in the series. If `false`, will only apply the given changes to the instance specified by `instanceStartDate`.
instanceStartDate (optional)	`string \| Date`	Date object representing the start time of the desired instance, if looking for a single instance of a recurring event. If this is not provided and id represents a recurring event, the first instance of that event will be returned by default.

Only for:

iOS

`Reminder`

A reminder record, used in the iOS Reminders app. No direct analog on Android.

Name	Type	Description
alarms (optional)	`Alarm[]`	Array of Alarm objects which control automated alarms to the user about the task.
calendarId (optional)	`string`	ID of the calendar that contains this reminder.
completed (optional)	`boolean`	Indicates whether or not the task has been completed.
completionDate (optional)	`string \| Date`	Date object or string representing the date of completion, if `completed` is `true`. Setting this property of a nonnull `Date` will automatically set the reminder's `completed` value to `true`.
creationDate (optional)	`string \| Date`	Date when the reminder record was created.
dueDate (optional)	`string \| Date`	Date object or string representing the time when the reminder task is due.
id (optional)	`string`	Internal ID that represents this reminder on the device.
lastModifiedDate (optional)	`string \| Date`	Date when the reminder record was last modified.
location (optional)	`string`	Location field of the reminder
notes (optional)	`string`	Description or notes saved with the reminder.
recurrenceRule (optional)	`RecurrenceRule`	Object representing rules for recurring or repeated reminders. Null for one-time tasks.
startDate (optional)	`string \| Date`	Date object or string representing the start date of the reminder task.
timeZone (optional)	`string`	Time zone the reminder is scheduled in.
title (optional)	`string`	Visible name of the reminder.
url (optional)	`string`	URL for the reminder.

`Source`

A source account that owns a particular calendar. Expo apps will typically not need to interact with Source objects.

Name	Type	Description
id (optional)	`string`	Only for: iOS Internal ID that represents this source on the device.
isLocalAccount (optional)	`boolean`	Only for: Android Whether this source is the local phone account. Must be `true` if `type` is `undefined`.
name	`string`	Name for the account that owns this calendar and was used to sync the calendar to the device.
type	`string`	Type of the account that owns this calendar and was used to sync it to the device. If `isLocalAccount` is falsy then this must be defined, and must match an account on the device along with `name`, or the OS will delete the calendar. On iOS, one of `SourceType`s.

Android Permission	Description
`READ_CALENDAR`	Allows an application to read the user's calendar data.
`WRITE_CALENDAR`	Allows an application to write the user's calendar data.

iOS

The following usage description keys are used by this library:

Info.plist Key	Description
`NSCalendarsUsageDescription`	A message that tells the user why the app is requesting access to the user’s calendar data.
`NSRemindersUsageDescription`	A message that tells the user why the app is requesting access to the user’s reminders.