2015.m

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
   NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
   dateFormatter.dateFormat = @"YYYY";
   NSDate *date = [NSDate dateWithTimeIntervalSince1970:1419872056];
    
   NSLog (@"%@", [dateFormatter stringFromDate:date]); // 2015
   
   dateFormatter.dateFormat = @"yyyy";
   NSLog(@"%@", [dateFormatter stringFromDate:date]); // 2014
   
   return 0;
}