Swift countdown timer- displays days hours seconds remaining

Question

Hello I am very new to swift and I was trying to create an app that counts down to an event on a specific date. I want it to show the number of days hours and seconds left until the specified date but I cannot figure out how to do this.

Please help!

what exactly dont you know ? Convert timestamp to days, hours, second (using `NSDate`) or update it every second (using `NSTimer`) ? — lukasbalaz7, Feb 09 '16 at 06:01
Duplicate: http://stackoverflow.com/questions/29374553/how-to-make-a-countdown-with-nstimer-on-swift — MarkP, Feb 09 '16 at 06:02

score 11 · Answer 1 · answered Jun 25 '18 at 13:49

Swift 4

var releaseDate: NSDate?
var countdownTimer = Timer()

func startTimer() {

    let releaseDateString = "2018-09-16 08:00:00"
    let releaseDateFormatter = DateFormatter()
    releaseDateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
    releaseDate = releaseDateFormatter.date(from: releaseDateString)! as NSDate

    countdownTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateTime), userInfo: nil, repeats: true)
}

@objc func updateTime() {

    let currentDate = Date()
    let calendar = Calendar.current

    let diffDateComponents = calendar.dateComponents([.day, .hour, .minute, .second], from: currentDate, to: releaseDate! as Date)

    let countdown = "Days \(diffDateComponents.day ?? 0), Hours \(diffDateComponents.hour ?? 0), Minutes \(diffDateComponents.minute ?? 0), Seconds \(diffDateComponents.second ?? 0)"

    print(countdown)
}

this code crashed on releaseDate = releaseDateFormatter.date(from: releaseDateString)! as NSDate this line....what is the problem? — Sptibo, Apr 20 '21 at 09:14

score 8 · Answer 2 · edited Jun 20 '20 at 09:12

This works like a charm:

var releaseDate: NSDate?

override func viewDidLoad() {
    super.viewDidLoad()

    let releaseDateString = "2016-03-02 22:00:00"
    let releaseDateFormatter = NSDateFormatter()
    releaseDateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
    releaseDate = releaseDateFormatter.dateFromString(releaseDateString)!
    
    NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "countDownDate", userInfo: nil, repeats: true)
}

func countDownDate() {
    let currentDate = NSDate()

    let diffDateComponents = NSCalendar.currentCalendar().components([NSCalendarUnit.Month, NSCalendarUnit.Day, NSCalendarUnit.Hour, NSCalendarUnit.Minute, NSCalendarUnit.Second], fromDate: currentDate, toDate: releaseDate!, options: .MatchFirst)
    
    let countdown = "Months: \(diffDateComponents.month), Days: \(diffDateComponents.day), Hours: \(diffDateComponents.hour), Minutes: \(diffDateComponents.minute), Seconds: \(diffDateComponents.second)"
    print(countdown)
}

score 6 · Answer 3 · answered Jun 18 '17 at 15:56

Swift 3

var releaseDate: Date? 

override func viewDidLoad() {
  super.viewDidLoad()     

  let releaseDateFormatter = DateFormatter()
  releaseDateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
  releaseDate = releaseDateFormatter.date(from:releaseDateString!)!

  Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.countDownDate), userInfo: nil, repeats: true)
}

func countDownDate() {
    let date = Date()
    let calendar = Calendar.current

    let diffDateComponents = calendar.dateComponents([.day, .hour, .minute, .second], from: date, to: releaseDate!)
    let countdown = "Days \(diffDateComponents.day),  Hours: \(diffDateComponents.hour), Minutes: \(diffDateComponents.minute), Seconds: \(diffDateComponents.second)"
    print(countdown)
}

daj mi spokój · Answer 4 · 2020-10-13T07:02:09.643

This is what I had to do for my app.

import UIKit
import Foundation

var timer = Timer()
var currentTime = Date()
var compareTime = Date().addingTimeInterval(-21600)


func setupButtonTitle()
{
   if UserDefaults.standard.object(forKey: "count6") == nil
   {
    button.setTitle("PRESS", for: .normal)
    button.backgroundColor = .green
   }
   else
   {
    button.setTitle("PRESS" + "\nIN " + "\(startTimer()))" , for: .normal)
   }
 button.addTarget(self, action: #selector(buttonTap), for: .touchUpInside)
}


func startTimer()
{
  timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(sixHourCountdown), userInfo: nil, repeats: true)
}

@objc func sixHourCountdown()
{
    let timeStarted = UserDefaults.standard.object(forKey: "count6")

    let timeStart = timeStarted as! Date
    let diffComponents = Calendar.current.dateComponents([.hour, .minute, .second], from: compareTime, to: timeStart)
    let hour = diffComponents.hour!
    let minute = diffComponents.minute!
    let second = diffComponents.second!
    let timeRemaining = String(format: "%02d:%02d:%02d", hour, minute, second)

    compareTime += 1

    if hour == 0 && minute == 0 && second == 0 || timeStart < compareTime
    {
        button.setTitle("PRESS", for: .normal)
        button.backgroundColor = .green
        timer.invalidate()
    }
    else
    {
        button.setTitle("PRESS IN" + "\n\(timeRemaining)", for: .normal)
    }
 }


@objc func buttonTap()
{
    if button.currentTitle != "PRESS"
    {
        button.backgroundColor = .red
        DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(2), execute:
        {
         button.backgroundColor = .yellow
        })
    }
    if button.currentTitle == "PRESS" && button.backgroundColor == .green
    {
        UserDefaults.standard.set(currentTime, forKey: "count6")

        let otherVC = OTHERVC()
        self.navigationController?.pushViewController(otherVC, animated: true)
    }
}


override func viewDidLoad() {
super.viewDidLoad()


setupButtonTitle()

Swift countdown timer- displays days hours seconds remaining

4 Answers4

This works like a charm: