how counting down the days in swift? - ios

Question

I am new to Swift and I have not worked with NSDate. For my app I need how to make to calculate how many days there are until the event. The date of the event is written with DatePicker on Firebase, and I need to calculate from the current date how many days are left until the day it's written. All I need is to count down the days.

Answer 1

Convert your data from DatePicker to Date object, and you can use the following function which returns an Int, a representation of the number of days to a passed date.
func daysTo(date: Date) -> Int? {
let calendar = Calendar.current
let date1 = calendar.startOfDay(for: Date())
let date2 = calendar.startOfDay(for: date)
let components = calendar.dateComponents([.day], from: date1, to: date2)
return components.day
}

Answer 2

you can use this extension for find difference between date:
extension Date {
public func diffrenceTime() -> (Int, Int) {
var cal = Calendar.init(identifier: .persian)
let d1 = Date()
let components = cal.dateComponents([.hour, .minute], from: self, to: d1)
let diffHour = components.hour!
let diffMinute = components.minute!
return (diffHour, diffMinute)
}
public func fullDistance(from date: Date, resultIn component: Calendar.Component, calendar: Calendar = .current) -> Int? {
calendar.dateComponents([component], from: self, to: date).value(for: component)
}
public func distance(from date: Date, only component: Calendar.Component, calendar: Calendar = .current) -> Int {
let days1 = calendar.component(component, from: self)
let days2 = calendar.component(component, from: date)
return days1 - days2
}
public func hasSame(_ component: Calendar.Component, as date: Date) -> Bool {
self.distance(from: date, only: component) == 0
}
}
example for use:
let dateOne = Date() // or any date
let dateTwo = getDateFromServer // your second date for
// option One
let distanceDay = dateOne.fullDistance(from: dateTwo, resultIn: .day)
var cal = Calendar.current // for your calendar
cal.locale = Locale.init(identifier: "EN")
// option Two
let distanceDay = dateOne.fullDistance(from: dateTwo, resultIn: .day, calendar: cal)
you can set hour, minute or any Component for find difference instead of day in result parameter