How to call function at 8:30am every day - ios

Question

Im trying to make a quiz app and I want it to show a new question every day at 8:30am and disappear at 6pm. I have seen online that the main way is to use timer but my question is if the person changes time zones, won't the timer be out of sync? Or does it restart every day? here is my code: (please note I am a beginner)
Also, whenever I load my app, the question appears for a second and then disappears and then appears again after the timer is up.
#objc func loadQuestion() {
questionView.alpha = 0
self.view.addSubview(questionView)
questionView.center = self.view.center
questionView.transform = CGAffineTransform.init(scaleX: 1.3, y: 1.3)
UIView.animate(withDuration: 0.4) {
self.visualEffectView.effect = self.effect
self.questionView.alpha = 1
self.questionView.transform = CGAffineTransform.identity
let date = Date().addingTimeInterval(30600)
let timer = Timer(fireAt: date, interval: 0, target: self, selector: #selector(self.loadQuestion), userInfo: nil, repeats: false)
RunLoop.main.add(timer, forMode: .common)
}
}
#objc func loadOutQuestion() {
UIView.animate(withDuration: 0.3, animations: {
self.questionView.transform = CGAffineTransform.init(scaleX: 1.3, y: 1.3)
self.questionView.alpha = 0
self.visualEffectView.effect = nil
let date = Date().addingTimeInterval(64800)
let timer = Timer(fireAt: date, interval: 0, target: self, selector: #selector(self.loadOutQuestion), userInfo: nil, repeats: false)
RunLoop.main.add(timer, forMode: .common)
}) { (succcess:Bool) in
self.questionView.removeFromSuperview()
}
}

Answer 1

You can use "Local Notification I put apple sample code please check it and you can modify sample code as per your requirement.
The steps for configuring a local notification are as follows:
Create and configure a UNMutableNotificationContent object with the notification details.
Create a UNCalendarNotificationTrigger, UNTimeIntervalNotificationTrigger, or UNLocationNotificationTrigger object to describe the conditions under which the notification is delivered.
Create a UNNotificationRequest object with the content and trigger information.
Call the addNotificationRequest:withCompletionHandler: method to schedule the notification; see Scheduling Local Notifications for Delivery
Official Document
Sample code
let content = UNMutableNotificationContent()
// Replace "Wake up!" with your "question title"
content.title = NSString.localizedUserNotificationString(forKey: "Wake up!", arguments: nil)
// Replace "Rise and shine! It's morning time!" with your "question description"
content.body = NSString.localizedUserNotificationString(forKey: "Rise and shine! It's morning time!",
arguments: nil)
// Configure the trigger for a 7am wakeup.
var dateInfo = DateComponents()
dateInfo.hour = 7
dateInfo.minute = 0
let trigger = UNCalendarNotificationTrigger(dateMatching: dateInfo, repeats: false)
// Create the request object.
let request = UNNotificationRequest(identifier: "MorningAlarm", content: content, trigger: trigger)

Answer 2

This is what I have so far. I don't know if Im getting closer or farther from resolving this issue
#objc func loadQuestion() {
self.view.addSubview(questionView)
questionView.center = self.view.center
questionView.transform = CGAffineTransform.init(scaleX: 1.3, y: 1.3)
questionView.alpha = 0
var dateComponents = DateComponents()
dateComponents.hour = 08
dateComponents.minute = 30
let currentTime = DateComponents()
let hour = currentTime.hour
let minute = currentTime.minute
var calendar = Calendar.current
calendar.timeZone = NSTimeZone.local
if hour >= dateComponents {
UIView.animate(withDuration: 0.4) {
self.visualEffectView.effect = self.effect
self.questionView.alpha = 1
self.questionView.transform = CGAffineTransform.identity
}
}
}

Answer 3

This will get 8:30am and 6:00pm from user's local time.
var calendar = Calendar.current
calendar.timeZone = NSTimeZone.local
let startDate = calendar.startOfDay(for: Date())
let EightAM = calendar.date(byAdding: .hour, value: 8, to: startDate)!
let EightThirtyAM = calendar.date(byAdding: .hour, value: 30, to: EightAM)!
let SixPM = calendar.date(byAdding: .hour, value: 18, to: startDate)!
If the App isn't open at these times, nothing will fire.
What you could do in this case is in ViewDidLoad, check
if Date() > EightThirtyAM && Date() < SixPM {
showQuiz()
} else {
hideQuiz()
}
If you want it to disappear at 6:00pm on the dot add
let timer = Timer(fireAt: SixPM, interval: 0, target: self, selector: #selector(hideQuiz), userInfo: nil, repeats: false)
RunLoop.main.add(timer, forMode: .common)
If you prefer a component solution try.
var calendar = Calendar.current
calendar.timeZone = NSTimeZone.local
let hours = calendar.component(.hour, from: Date())
let minutes = calendar.component(.minute, from: Date())
let timeFloat:Float = Float(hours) + Float(minutes)/60
if timeFloat > 8.5 && timeFloat < 18 {
showQuiz
} else {
hideQuiz
}