How to schedule and repeat local notification - ios

Question

I'm trying to make an application to help quitting smoking,
I need the user to enter his first cigarette time, and the time between each cigarette , and finally the added time to increase time between each cigarette. and at this time I send a local notification.
Ex: let say his first cigarette at 7:00 AM and he smokes 1 cigarette every 1 Hr and he want to add extra 10 min.
so 1st cigarette : 7:00
2nd : 8:10/
3rd : 9:20/
4th :10:30 .. etc
I tried a lot of solutions but I have some problems about date format that I got from picker views, I need them to be like "hh:MM a"
Any help?

Answer 1

To get a date in a different format, you can create a NSDate from a Date object and then use NSDateFormatter to format:
let date=NSDate(timeInterval: 0, since: yourDate)
let dateFormatter=DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US")
dateFormatter.setLocalizedDateFormatFromTemplate("hh:mm a")
String dateString=dateFormatter.string(from: date)
You can get the initial date object from the UIDatePicker or when it changes and a method is called in its delegate.

Answer 2

first create a date object with
let date = Date(timeIntervalSinceNow: 3600) // it may be any date whatever you want
To create the trigger from the date components:
let triggerDaily = Calendar.current.dateComponents([hour,.minute,.second,], from: date)
Now pass that date in UNCalendarNotificationTrigger with repeats true
let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDaily, repeats: true)
Create a date with time :
let formatter = DateFormatter()
formatter.dateFormat = "yyyy/MM/dd HH:mm"
let someDateTime = formatter.date(from: "2016/10/08 22:31") // put your date and time here
if Locale specific time :
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")

Answer 3

Well the solution suggested isn't elegant enough, so you have to create one notification for every hour, instead use this trigger
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: (60*60) + (10*60), repeats: true)
60*60 being the hour you mentioned and 10*60 being the 10 minute, set repeating to true and viola, your notification now triggers every 70 minutes.