Working with Calendar (expo-calendar)

1. Requesting Calendar Permissions

Permission	Scope	Description
Calendar	`calendar.read`	Allows reading calendar events and details
Calendar	`calendar.write`	Allows creating and modifying calendar events

Example: Requesting Calendar Permissions

import * as Calendar from 'expo-calendar';

const getCalendarPermissions = async () => {
  const { status } = await Calendar.requestCalendarPermissionsAsync();
  if (status === 'granted') {
    console.log('Calendar permissions granted');
  } else {
    console.log('Calendar permissions denied');
  }
};

getCalendarPermissions();

2. Getting Calendars

Property	Description	Notes
id	Unique identifier for the calendar	Read-only
name	Name of the calendar	Editable
color	Color associated with the calendar	Hex color code or named color
type	Type of calendar (e.g., LOCAL, EXCHANGE)	Read-only
ownerAccount	Owner account of the calendar	Read-only
allowsModifications	Indicates if calendar can be modified	Boolean

Example: Fetching Calendars

import * as Calendar from 'expo-calendar';

const calendars = await Calendar.getCalendarsAsync();
console.log(calendars);

Note: You must request calendar permissions before fetching calendars.

3. Creating Calendar Events

Property	Description	Example Value
title	Title of the event	`"Team Meeting"`
startDate	Start date and time of the event (ISO 8601)	`"2025-04-10T10:00:00Z"`
endDate	End date and time of the event (ISO 8601)	`"2025-04-10T11:00:00Z"`
location	Location of the event	`"Conference Room A"`
description	Description or notes for the event	`"Quarterly planning session"`
calendarId	ID of the calendar to create the event in	`"123456789"`

Example: Creating a Calendar Event

import * as Calendar from &#x27;expo-calendar&#x27;;

const event = {
  title: &#x27;Team Meeting&#x27;,
  startDate: &#x27;2025-04-10T10:00:00Z&#x27;,
  endDate: &#x27;2025-04-10T11:00:00Z&#x27;,
  location: &#x27;Conference Room A&#x27;,
  description: &#x27;Quarterly planning session&#x27;,
  calendarId: &#x27;123456789&#x27;
};

const eventId = await Calendar.createEventAsync(event);
console.log(&#x27;Event created with ID:&#x27;, eventId);

Note: Ensure the calendar ID corresponds to a valid calendar accessible by the app.

4. Updating Events

Property	Description	Values
id	Unique identifier for the event	`string`
title	Title of the event	`string`
startDate	Start date and time of the event	`Date`
endDate	End date and time of the event	`Date`
location	Location of the event	`string`
description	Description of the event	`string`
calendarId	ID of the calendar to which the event belongs	`string`

Example: Updating an Event

import * as Calendar from 'expo-calendar';

const updateEvent = async () => {
  const eventId = '12345';
  const updatedEvent = {
    id: eventId,
    title: 'Updated Meeting',
    startDate: new Date('2026-04-15T10:00:00'),
    endDate: new Date('2026-04-15T11:00:00'),
    location: 'Conference Room B',
    description: 'Updated meeting description',
    calendarId: 'calendar-id'
  };

  await Calendar.updateEventAsync(eventId, updatedEvent);
};

updateEvent();

5. Deleting Events

Method	Description	Notes
deleteEventAsync	Deletes an event from the calendar	Requires event ID and calendar ID

Example: Deleting an Event

import { deleteEventAsync } from 'expo-calendar';

const eventId = '12345';
const calendarId = '67890';

await deleteEventAsync(eventId, calendarId);

Note: Ensure the event ID and calendar ID are valid before deletion.

6. Getting Events

Property	Description	Example
id	Unique identifier for the event	`"12345"`
title	Title of the event	`"Team Meeting"`
startDate	Start date and time of the event	`"2025-04-10T10:00:00Z"`
endDate	End date and time of the event	`"2025-04-10T11:00:00Z"`
calendarId	ID of the calendar the event belongs to	`"cal-123"`
location	Location of the event	`"Conference Room A"`
description	Description or notes about the event	`"Quarterly planning session"`

Example: Fetching Events from Calendar

import * as Calendar from &#x27;expo-calendar&#x27;;

const getEvents = async () => {
  const events = await Calendar.getEventsAsync(
    &#x27;cal-123&#x27;,
    new Date(&#x27;2025-04-10T00:00:00Z&#x27;),
    new Date(&#x27;2025-04-11T00:00:00Z&#x27;)
  );
  console.log(events);
};

getEvents();

Note: Ensure that the calendar ID is valid and accessible to the user.

7. Creating Reminders (iOS)

Property	Description	Values
title	Title of the reminder	`string`
calendarId	ID of the calendar to create the reminder in	`string`
startDate	Start date and time of the reminder	`Date`
endDate	End date and time of the reminder	`Date`
location	Location associated with the reminder	`string`
notes	Additional notes for the reminder	`string`
allDay	Flag to indicate if the reminder is all-day	`boolean`
reminderDate	Date and time for the reminder alert	`Date`

Example: Creating a Reminder

import * as Calendar from 'expo-calendar';

const createReminder = async () => {
  const calendarId = 'your-calendar-id';
  const reminder = {
    title: 'Meeting with team',
    calendarId,
    startDate: new Date(2025, 10, 15, 10, 0),
    endDate: new Date(2025, 10, 15, 11, 0),
    location: 'Conference Room A',
    notes: 'Discuss project timeline',
    allDay: false,
    reminderDate: new Date(2025, 10, 15, 9, 30),
  };

  try {
    const reminderId = await Calendar.createReminderAsync(reminder);
    console.log('Reminder created with ID:', reminderId);
  } catch (error) {
    console.error('Error creating reminder:', error);
  }
};

Note: On iOS, reminders must be created in a calendar that supports reminders. Ensure the calendar has the appropriate permissions.

8. Setting Event Recurrence

Property	Values	Description
recurrenceRule	`RRULE`	Defines the recurrence pattern using iCalendar RRULE format
recurrenceEnd	`Date`	End date for the recurring event
recurrenceCount	`number`	Number of times the event should repeat (alternative to end date)

Example: Setting Daily Recurrence

import { Calendar } from 'expo-calendar';

const event = {
  title: 'Daily Standup',
  startDate: new Date(2026, 5, 15, 9, 0),
  endDate: new Date(2026, 5, 15, 10, 0),
  recurrenceRule: {
    frequency: 'DAILY',
    interval: 1,
    endDate: new Date(2026, 5, 30),
  },
};

const eventId = await Calendar.createEventAsync(
  calendarId,
  event
);

Example: Weekly Recurrence with Count

const weeklyEvent = {
  title: 'Weekly Team Meeting',
  startDate: new Date(2026, 5, 15, 14, 0),
  endDate: new Date(2026, 5, 15, 15, 0),
  recurrenceRule: {
    frequency: 'WEEKLY',
    interval: 1,
    count: 10,
  },
};

const eventId = await Calendar.createEventAsync(
  calendarId,
  weeklyEvent
);

Note: The recurrenceRule object supports various frequency types like DAILY, WEEKLY, MONTHLY, and YEARLY. The interval property specifies the interval between occurrences (e.g., every 2 weeks). The count and endDate properties are mutually exclusive.

9. Adding Event Alarms

Property	Values	Description
alarmDate	`Date`	The date and time when the alarm should trigger. Must be a valid JavaScript Date object.
alarmType	`'DISPLAY'` \| `'EMAIL'` \| `'SILENT'`	Specifies how the alarm should be delivered. `'DISPLAY'` shows a notification, `'EMAIL'` sends an email (if supported), and `'SILENT'` triggers silently.
alarmOffset	`number`	Number of minutes before the event starts to trigger the alarm. Positive values mean the alarm triggers before the event.

Example: Adding an Event with Alarm

import * as Calendar from 'expo-calendar';

const event = {
  title: 'Team Meeting',
  startDate: new Date(2026, 5, 15, 10, 0),
  endDate: new Date(2026, 5, 15, 11, 0),
  alarms: [
    {
      alarmDate: new Date(2026, 5, 15, 9, 30),
      alarmType: 'DISPLAY',
      alarmOffset: 30,
    },
  ],
};

const eventId = await Calendar.createEventAsync(event);

10. Opening Calendar App

Property	Description	Notes
openCalendarAsync	Opens the native calendar app	Available on iOS and Android

Example: Opening Calendar App

import { openCalendarAsync } from 'expo-calendar';

await openCalendarAsync();

11. Getting Event Details

Property	Description	Example
id	Unique identifier for the event	`"12345"`
title	Title of the event	`"Team Meeting"`
startDate	Start date and time of the event	`"2025-04-10T10:00:00Z"`
endDate	End date and time of the event	`"2025-04-10T11:00:00Z"`
location	Location of the event	`"Conference Room A"`
description	Description or notes about the event	`"Discuss Q2 goals and roadmap"`
calendarId	ID of the calendar this event belongs to	`"cal_abc123"`

Example: Fetching Event Details

import { Calendar } from 'expo-calendar';

const getEventDetails = async (eventId) => {
  try {
    const event = await Calendar.getEventAsync(eventId);
    console.log('Event Title:', event.title);
    console.log('Start Date:', event.startDate);
    console.log('End Date:', event.endDate);
  } catch (error) {
    console.error('Error fetching event details:', error);
  }
};

getEventDetails('12345');

Note: Ensure that the user has granted necessary permissions to access calendar data before calling getEventAsync.

12. Filtering Events by Date

Property	Description	Values
startDate	Date to start filtering from	`ISO 8601 string`
endDate	Date to end filtering at	`ISO 8601 string`

Example: Filter Events by Date Range

import * as Calendar from 'expo-calendar';

const filterEvents = async () => {
  const events = await Calendar.getEventsAsync({
    startDate: '2025-01-01T00:00:00Z',
    endDate: '2025-01-31T23:59:59Z'
  });

  console.log(events);
};