I am relatively new to coding and put together this countdown timer based on code available in various public forums. This countdown timer for my iPhone puts a timer on my screen, allows me to select the time counted down in minutes and seconds, then to start the timer and, if so desired, reset it.While such timers are readily available, I wanted to try and build one myself and learn swift in the process. The program builds and runs fine. However the latter section is intended to play a chime when the countdown timer reaches the 1/2 way point and then when it finishes. This is not working and I'm at a loss to get it to do so. I would appreciate it if someone would modify my code to make this work. Also, I don't know how to compile the program so that I can move it off my MacBook and onto my iPad and would appreciate guidance on that. The code follows: Thank you // // Content-ViewModel.swift // Countdown Timer // // // import Foundation import AVFoundation extension ContentView { //contains the initial user interface final class ViewModel: ObservableObject { @Published var isActive = false @Published var showingAlert = false @Published var time: String = "1:00" @Published var minutes: Float = 1.0 { didSet { self.time = "\(Int(minutes)):00" } } private var initialTime = 0 // sets the var initialTime to 0 private var endDate = Date() // sets endDate to the current date // this next func starts timer in minutes func start(minutes: Float) { // this starts timer in minutes self.initialTime = Int(minutes) self.endDate = Date() self.isActive = true // true means the timer is active self.endDate = Calendar.current.date(byAdding: .minute, value: Int(minutes), to: endDate)! } // this next func updates the var minutes to original time func reset() { self.minutes = Float(initialTime) self.isActive = false self.time = "\(Int(minutes)):00" } // this next func calculates the elapsed time func updateCountDown() { guard isActive else { return } let now = Date() let diff = endDate.timeIntervalSince1970 - now.timeIntervalSince1970 if diff <= 0 { // means timer is at zero self.isActive = false self.time = "0:00" self.showingAlert = true return // coud add code here to signify time is up } // This next code allows us to grab minutes and seconds from the calendar let date = Date(timeIntervalSince1970: diff) let calendar = Calendar.current let minutes = calendar.component(.minute, from: date) let seconds = calendar.component(.second, from: date) self.minutes = Float(minutes) self.time = String(format: "%d:%02d", minutes, seconds) // this creates the 2 digit display of minutes and seconds as a string let halftime = minutes/2 // This shoud create a float variable equal to 1/2 run time let chimesSoundEffect = "Chimes-sound-effect.mp3" /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% */ var player: AVAudioPlayer? func playSound() { guard let url = Bundle.main.url(forResource: "sound", withExtension: "mp3") else { return } do { try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default) try AVAudioSession.sharedInstance().setActive(true) player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileType.mp3.rawValue) guard let player = player else { return } player.play() } catch let error { print(error.localizedDescription) } let timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in /* why doesn't the sound play when the halftime reached minutes/2 or when time reaches 0 */ if minutes == halftime { playSound() if minutes == 0 { timer.invalidate() playSound() } } } } } } }