How to calculate the age based on NSDate

Question

how to calculate the age based on the birth date in this format 6/24/1976 mon/date/year...

Answer 1

May be I'm wrong, but this is simpler, isn't it?

NSTimeInterval ageInterval = [birthDate timeIntervalSinceDate:[NSDate date]];

NSInteger age = ABS(ageInterval / (60 * 60 * 24 * 365));

Answer 2

Here's a function to calculate age (Swift 2.1)

func calculateAge (birthday: NSDate) -> NSInteger {

    let calendar : NSCalendar = NSCalendar.currentCalendar()
    let unitFlags : NSCalendarUnit = [NSCalendarUnit.Year, NSCalendarUnit.Month, NSCalendarUnit.Day]
    let dateComponentNow : NSDateComponents = calendar.components(unitFlags, fromDate: NSDate())
    let dateComponentBirth : NSDateComponents = calendar.components(unitFlags, fromDate: birthday)

    if ( (dateComponentNow.month < dateComponentBirth.month) ||
        ((dateComponentNow.month == dateComponentBirth.month) && (dateComponentNow.day < dateComponentBirth.day))
        )
    {
        return dateComponentNow.year - dateComponentBirth.year - 1
    }
    else {
        return dateComponentNow.year - dateComponentBirth.year
    }
}

Answer 3

A simple to use swift extension to get the age/how old is a NSDate

extension NSDate {
    var age: Int {
        let calendar: NSCalendar = NSCalendar.currentCalendar()
        let now = calendar.startOfDayForDate(NSDate())
        let birthdate = calendar.startOfDayForDate(self)
        let components = calendar.components(.Year, fromDate: birthdate, toDate: now, options: [])
        return components.year
    }
}

Exemple:

NSDate(timeIntervalSince1970:0).age // => 45 (as of nov 2015) Epoch happened 45 year ago !

By the way, you should be careful, this is the western conception of age, the counting is different in some other countries (Korea for exemple).

Answer 4

Method in Swift 3+ syntax based on cobbal's solution.

func calculateAgeInYearsFromDateOfBirth (birthday: Date) -> Int {
        let now = Date()
        let calendar = Calendar.current

        let ageComponents = calendar.dateComponents([.year], from: birthday, to: now)
        let age = ageComponents.year!
        return age
    }

Answer 5

If u want to find age alone .use below one which include leap year calculation too

- (NSInteger)age:(NSDate *)dateOfBirth {
    NSCalendar *calendar = [NSCalendar currentCalendar];
    unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
    NSDateComponents *dateComponentsNow = [calendar components:unitFlags fromDate:[NSDate date]];
    NSDateComponents *dateComponentsBirth = [calendar components:unitFlags fromDate:dateOfBirth];

    if (([dateComponentsNow month] < [dateComponentsBirth month]) ||
        (([dateComponentsNow month] == [dateComponentsBirth month]) && ([dateComponentsNow day] < [dateComponentsBirth day]))) {
        return [dateComponentsNow year] - [dateComponentsBirth year] - 1;
    } else {
        return [dateComponentsNow year] - [dateComponentsBirth year];
    }
}