Count down day 1 from each month - ios

Question

I am trying to make a counter that count day 1 from each month and reset it self for next month when it reaches that specific day.
Here's my code:
let date = NSDate()
let calendar = Calendar.current
let currentDate = calendar.date(from: components)
let userCalendar = Calendar.current
// here we set the due date. When the timer is supposed to finish
let competitionDate = NSDateComponents()
competitionDate.year = components.year!
competitionDate.month = components.month!
competitionDate.day = 9
competitionDate.hour = 00
competitionDate.minute = 00
let competitionDay = userCalendar.date(from: competitionDate as DateComponents)!
//here we change the seconds to hours,minutes and days
let CompetitionDayDifference = calendar.dateComponents([.day, .hour, .minute], from: Date().startOfMonth(), to: competitionDay)
//finally, here we set the variable to our remaining time
let daysLeft = CompetitionDayDifference.day
let hoursLeft = CompetitionDayDifference.hour
let minutesLeft = CompetitionDayDifference.minute
print(daysLef)
counter.value = CGFloat(daysLeft!)
The problem with this code is when it reaches day 0 it never reset it self back to count from current date to next month day # 9

Answer 1

You should use Calendar method func nextDate(after date: Date, matching components: DateComponents, matchingPolicy: Calendar.MatchingPolicy, repeatedTimePolicy: Calendar.RepeatedTimePolicy = default, direction: Calendar.SearchDirection = default) -> Date?, pass the day date component to it, use matchingPolicy .strict, repeatedTimePolicy .first and direction .forward to find the next date occurrence. Then you just need to use Calendar method func dateComponents(_ components: Set<Calendar.Component>, from start: Date, to end: Date) -> DateComponents and pass the date components that you want returned (day, hour, minute):
extension Date {
func timeLeftUntil(day: Int) -> (day: Int, hour: Int, minute: Int) {
precondition(1...28 ~= day, "paycheck day \(day) is out of range 1...28")
let nextDate = Calendar.current.nextDate(after: self, matching: DateComponents(day: day), matchingPolicy: .strict, repeatedTimePolicy: .first, direction: .forward)!
let dateComponents = Calendar.current.dateComponents([.day,.hour,.minute], from: self, to: nextDate)
return (dateComponents.day!, dateComponents.hour!, dateComponents.minute!)
}
}
Usage:
Date().timeLeftUntil(day: 25) // (day 23, hour 0, minute 39)