eventkit

name eventkit description Create, read, and manage calendar events and reminders using EventKit and EventKitUI. Use when adding events to the user's calendar, creating reminders, setting recurrence rules, requesting calendar or reminders access, presenting event editors, choosing calendars, handling alarms, observing calendar changes, or working with EKEventStore, EKEvent, EKReminder, EKCalendar, EKRecurrenceRule, EKEventEditViewController, EKCalendarChooser, or EventKitUI views. EventKit Use EventKit for calendar and reminder authorization, CRUD, recurrence, alarms, and system editors. Contents Availability Setup Authorization Creating Events Fetching Events Reminders Recurrence Rules Alarms EventKitUI Controllers Observing Changes Common Mistakes Review Checklist References Availability iOS 17+: Use granular full/write-only request methods; legacy requestAccess(to:) no longer prompts and throws. The system event editor can create an event without app calendar access. For iOS 10–16, guard those APIs, use the legacy request plus NSCalendarsUsageDescription / NSRemindersUsageDescription ; EventKitUI may also need NSContactsUsageDescription . iOS 26+: The typed EKEventStore.EventStoreChanged / .changed message is available behind a guard. Keep EKEventStoreChanged for earlier systems. Setup Info.plist Keys Add the usage description for the access path selected in Authorization . Do not request broader access merely to simplify the setup path. The authorization-free system editor path needs no calendar usage string. Direct writes need write-only or full access; reads need full access. Reminders have only full access. Event Store Create a single EKEventStore instance and reuse it. Do not mix objects from different event stores. import EventKit let eventStore = EKEventStore () Authorization Request the narrowest access that matches the feature. Apply the versioned request path in Availability . Key Access Level NSCalendarsFullAccessUsageDescription Read + write events NSCalendarsWriteOnlyAccessUsageDescription Direct write-only event creation NSRemindersFullAccessUsageDescription Read + write reminders Full Access to Events Call try await eventStore.requestFullAccessToEvents() when the app needs to read, edit, delete, or fetch calendar events. Write-Only Access to Events Use when your app only creates events (e.g., saving a booking) and does not need to read existing events. Call try await eventStore.requestWriteOnlyAccessToEvents() before direct EventKit writes that do not use EKEventEditViewController . Write-only access can create events but cannot fetch calendars or events, including app-created events. Use full access for later query, verification, modification, or sync. Full Access to Reminders Call try await eventStore.requestFullAccessToReminders() before reading, creating, editing, or deleting reminders. Checking Authorization Status Use EKEventStore.authorizationStatus(for: .event) or .reminder before work. Handle .notDetermined , .fullAccess , .writeOnly , .restricted , .denied , and @unknown default ; only .fullAccess supports event/reminder reads. Creating Events func createEvent ( title : String , startDate : Date , endDate : Date , calendar : EKCalendar ? = nil ) throws { let event = EKEvent (eventStore: eventStore) event.title = title event.startDate = startDate event.endDate = endDate event.calendar = calendar ?? eventStore.defaultCalendarForNewEvents try eventStore.save(event, span: .thisEvent) } Setting a Specific Calendar // List writable calendars let calendars = eventStore.calendars(for: .event) .filter { $0 .allowsContentModifications } // Use the first writable calendar, or the default let targetCalendar = calendars.first ?? eventStore.defaultCalendarForNewEvents event.calendar = targetCalendar Adding Structured Location import CoreLocation let location = EKStructuredLocation (title: "Apple Park" ) location.geoLocation = CLLocation (latitude: 37.3349 , longitude: - 122.0090 ) event.structuredLocation = location Fetching Events After the full-access gate in Authorization , use a date-range predicate to query events. The events(matching:) method returns occurrences of recurring events expanded within the range. Event predicates are capped to a four-year span, and events(matching:) / enumerateEvents(matching:using:) are synchronous and return only committed events. func fetchEvents ( from start : Date , to end : Date ) -> [ EKEvent ] { let predicate = eventStore.predicateForEvents( withStart: start, end: end, calendars: nil // nil = all calendars ) return eventStore.events(matching: predicate) .sorted { $0 .startDate < $1 .startDate } } Fetching a Single Event by Identifier if let event = eventStore.event(withIdentifier: savedEventID) { print (event.title ?? "No title" ) } Reminders Creating a Reminder func createReminder ( title : String , dueDate : Date ) throws { let reminder = EKReminder (eventStore: eventStore) reminder.title = title reminder.calendar = eventStore.defaultCalendarForNewReminders() let dueDateComponents = Calendar .current.dateComponents( [.year, .month, .day, .hour, .minute], from: dueDate ) reminder.dueDateComponents = dueDateComponents try eventStore.save(reminder, commit: true ) } Fetching Reminders Reminder fetches are asynchronous and return through a completion handler. func fetchIncompleteReminders () async -> [ EKReminder ] { let predicate = eventStore.predicateForIncompleteReminders( withDueDateStarting: nil , ending: nil , calendars: nil ) return await withCheckedContinuation { continuation in eventStore.fetchReminders(matching: predicate) { reminders in continuation.resume(returning: reminders ?? []) } } } Completing a Reminder func completeReminder ( _ reminder : EKReminder ) throws { reminder.isCompleted = true try eventStore.save(reminder, commit: true ) } Recurrence Rules Use EKRecurrenceRule to create repeating events or reminders. Simple Recurrence // Every week, indefinitely let weeklyRule = EKRecurrenceRule ( recurrenceWith: .weekly, interval: 1 , end: nil ) event.addRecurrenceRule(weeklyRule) // Every 2 weeks, ending after 10 occurrences let biweeklyRule = EKRecurrenceRule ( recurrenceWith: .weekly, interval: 2 , end: EKRecurrenceEnd (occurrenceCount: 10 ) ) // Monthly, ending on a specific date let monthlyRule = EKRecurrenceRule ( recurrenceWith: .monthly, interval: 1 , end: EKRecurrenceEnd (end: endDate) ) Complex Recurrence // Every Monday and Wednesday let days = [ EKRecurrenceDayOfWeek (.monday), EKRecurrenceDayOfWeek (.wednesday) ] let complexRule = EKRecurrenceRule ( recurrenceWith: .weekly, interval: 1 , daysOfTheWeek: days, daysOfTheMonth: nil , monthsOfTheYear: nil , weeksOfTheYear: nil , daysOfTheYear: nil , setPositions: nil , end: nil ) event.addRecurrenceRule(complexRule) Editing Recurring Events When saving changes to a recurring event, specify the span: // Change only this occurrence try eventStore.save(event, span: .thisEvent) // Change this and all future occurrences try eventStore.save(event, span: .futureEvents) Alarms Attach alarms to events or reminders to trigger notifications. // 15 minutes before let alarm = EKAlarm (relativeOffset: - 15 * 60 ) event.addAlarm(alarm) // At an absolute date let absoluteAlarm = EKAlarm (absoluteDate: alertDate) event.addAlarm(absoluteAlarm) For reminder geofences, put an EKStructuredLocation and .enter / .leave proximity on an EKAlarm , then add it to the reminder. See references/eventkit-patterns.md for the full location-based reminder pattern. EventKitUI Controllers EKEventEditViewController — Create/Edit Events Present the system event editor for creating or editing events. On the authorization-free path in Availability , the editor runs out of process with its own calendar access. Do not inspect the dismissed controller to learn what was saved; refetch only with separate full access. import EventKitUI class EventEditorCoordinator : NSObject , EKEventEditViewDelegate { let eventStore = EKEventStore () func presentEditor ( from viewController : UIViewController ) { let editor = EKEventEditViewController () editor.eventStore = eventStore editor.editViewDelegate = self viewController.present(editor, animated: true ) } func eventEditViewController ( _ controller : EKEventEditViewController , didCompleteWith action : EKEventEditViewAction ) { switch action { case .saved: // Event saved break case .canceled: break case .deleted: break @unknown default : break } controller.dismiss(animated: true ) } } EKEventViewController — View an Event import EventKitUI let viewer = EKEventViewController () viewer.event = existingEvent viewer.allowsEditing = true navigationController ? .pushViewController(viewer, animated: true ) EKCalendarChooser — Select Calendars EKCalendarChooser requires write-only or full calendar access. In write-only apps, the chooser behaves as writable-calendars-only and only allows a single writable calendar selection. let chooser = EKCalendarChooser ( selectionStyle: .multiple, displayStyle: .allCalendars, entityType: .event, eventStore: eventStore ) chooser.showsDoneButton = true chooser.showsCancelButton = true chooser.delegate = self present( UINavigationController (rootViewController: chooser), animated: true ) Observing Changes Register for EKEventStoreChanged notifications to keep your UI in sync when events are modified outside your app (e.g., by the Calendar app or a sync). NotificationCenter .default.addObserver( forName: . EKEventStoreChanged , object: eventStore, queue: .main ) { [ weak self ] _ in self ? .refreshEvents() } Always re-fetch events after receiving this notification. Previously fetched EKEvent , EKReminder , and EKCalendar objects may be stale. The notification is posted on the main actor. Common Mistakes DON'T: Use legacy requestAccess(to:) on current systems // WRONG: Legacy request API on current systems eventStore.requestAccess(to: .event) { granted, error in } // CORRECT: Use the granular async methods let granted = try await eventStore.requestFullAccessToEvents() Keep it only in the compatibility fallback from Availability . DON'T: Save events to a read-only calendar // WRONG: No check -- will throw if calendar is read-only event.calendar = someCalendar try eventStore.save(event, span: .thisEvent) // CORRECT: Verify the calendar allows modifications guard someCalendar.allowsContentModifications else { event.calendar = eventStore.defaultCalendarForNewEvents return } event.calendar = someCalendar try eventStore.save(event, span: .thisEvent) DON'T: Ignore timezone when creating events // WRONG: Event appears at wrong time for traveling users event.startDate = Date () event.endDate = Date ().addingTimeInterval( 3600 ) // CORRECT: Set the timezone explicitly for location-specific events event.timeZone = TimeZone (identifier: "America/New_York" ) event.startDate = startDate event.endDate = endDate DON'T: Forget to commit batched saves // WRONG: Changes never persisted try eventStore.save(event1, span: .thisEvent, commit: false ) try eventStore.save(event2, span: .thisEvent, commit: false ) // Missing commit! // CORRECT: Commit after batching try eventStore.save(event1, span: .thisEvent, commit: false ) try eventStore.save(event2, span: .thisEvent, commit: false ) try eventStore.commit() DON'T: Mix EKObjects from different event stores // WRONG: Event fetched from storeA, saved to storeB let event = storeA.event(withIdentifier: id) ! try storeB.save(event, span: .thisEvent) // Undefined behavior // CORRECT: Use the same store throughout let event = eventStore.event(withIdentifier: id) ! try eventStore.save(event, span: .thisEvent) Review Checklist Correct Info.plist usage description keys added for calendars and/or reminders Authorization follows the version split in Availability Write-only calendar access used only for direct event creation, not event/calendar reads Authorization status checked before fetching or saving Full access required before any event or reminder fetch Single EKEventStore instance reused across the app Events saved to a writable calendar ( allowsContentModifications checked) Recurring event saves specify correct EKSpan ( .thisEvent vs .futureEvents ) Batched saves validate writable calendars, stage with commit: false , call throwing commit() , and on failure reset() unsaved state, discard every invalidated EKObject , then refetch or reconstruct before retry EKEventStoreChanged notification observed to refresh stale data Change observation uses the classic notification or guarded typed message per Availability Timezone set explicitly for location-specific events EKObjects not shared across different event store instances EventKitUI delegates dismiss controllers in completion callbacks References Extended patterns (SwiftUI wrappers, predicate queries, batch operations): references/eventkit-patterns.md EventKit framework EKEventStore EKEvent EKReminder EKRecurrenceRule EKCalendar EventKit UI EKEventEditViewController EKCalendarChooser Accessing the event store Creating a recurring event