Swift countdown timer- displays days hours seconds remaining - swift

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!

Answer 1

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)
}

Answer 2

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)
}

Answer 3

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)
}

Answer 4

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()