Adding an event to the calendar

Add:

Privacy - Calendars Usage Description to plist.info

import EventKit

Then:

func addEventToCalendar(title: String, description: String?, startDate: Date, endDate: Date, completion: ((_ success: Bool, _ error: NSError?) -> Void)? = nil) {
    let eventStore = EKEventStore()

    eventStore.requestAccess(to: .event, completion: { (granted, error) in
        if (granted) && (error == nil) {
            let event = EKEvent(eventStore: eventStore)
            event.title = title
            event.startDate = startDate
            event.endDate = endDate
            event.notes = description
            event.calendar = eventStore.defaultCalendarForNewEvents
            do {
                try eventStore.save(event, span: .thisEvent)
            } catch let e as NSError {
                completion?(false, e)
                return
            }
            completion?(true, nil)
        } else {
            completion?(false, error as NSError?)
        }
    })
}