Calculate age from NSDate

NSDate+Age.h

//
//  NSDate+Age.h
//
//  Created by Alex Yao on 7/8/12.
//  Copyright (c) 2012 alex@thecellcity.com. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSDate (Age)
- (NSInteger)age;
@end

NSDate+Age.m

//
//  NSDate+Age.m
//
//  Created by Alex Yao on 7/8/12.
//  Copyright (c) 2012 alex@thecellcity.com. All rights reserved.
//

#import "NSDate+Age.h"

@implementation NSDate (Age)
- (NSInteger)age
{
    NSDateComponents *timeOnEarth = [[NSCalendar currentCalendar] components:NSYearCalendarUnit fromDate:self toDate:[NSDate date] options:0];
    return [timeOnEarth year];
}
@end