Skill v1.0.5

currentAutomated scan100/100

dpearson2699/swift-ios-skills/eventkit

~3 modified

──Details

PublishedJuly 22, 2026 at 05:33 PM

Content Hashsha256:93221a4d7da69bf8...

Git SHA90c957327253

Bump Typepatch

Compare with v1.0.4

──Files

Files (1 file, 15.0 KB)

SKILL.md15.0 KBactive

SKILL.md · 498 lines · 15.0 KB

version: "1.0.5" 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.

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.

swift

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

swift

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

swift

// 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

swift

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.

swift

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

swift

if let event = eventStore.event(withIdentifier: savedEventID) {
    print(event.title ?? "No title")
}

Reminders

Creating a Reminder

swift

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.

swift

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

swift

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

swift

// 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

swift

// 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:

swift

// 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.

swift

// 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.

swift

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

swift

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.

swift

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).

swift

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

swift

// 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

swift

// 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

swift

// 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

swift

// 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

swift

// 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

← v1.0.4 All versions

Skill v1.0.5

EventKit

Contents

Availability

Setup

Info.plist Keys

Event Store

Authorization

Full Access to Events

Write-Only Access to Events

Full Access to Reminders

Checking Authorization Status

Creating Events

Setting a Specific Calendar

Adding Structured Location

Fetching Events

Fetching a Single Event by Identifier

Reminders

Creating a Reminder

Fetching Reminders

Completing a Reminder

Recurrence Rules

Simple Recurrence

Complex Recurrence

Editing Recurring Events

Alarms

EventKitUI Controllers

EKEventEditViewController — Create/Edit Events

EKEventViewController — View an Event

EKCalendarChooser — Select Calendars

Observing Changes

Common Mistakes

DON'T: Use legacy requestAccess(to:) on current systems

DON'T: Save events to a read-only calendar

DON'T: Ignore timezone when creating events

DON'T: Forget to commit batched saves

DON'T: Mix EKObjects from different event stores

Review Checklist

References