计算两个日期之间相差几天几小时几分钟

NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];

   [dateFormatter setDateFormat : @"yyyy-MM-dd HH:mm:ss" ];
   NSDate *  senddate=[ NSDate date ];
   //结束时间
   NSDate *endDate = [dateFormatter dateFromString : @"2014-6-24 00:00:00" ];
   //当前时间
   NSDate *senderDate = [dateFormatter dateFromString :[dateFormatter stringFromDate :senddate]];
   //得到相差秒数
   NSTimeInterval time=[endDate timeIntervalSinceDate :senderDate];

   int days = (( int )time)/( 3 6 0 0 * 2 4 );
   int hours = (( int )time)%( 3 6 0 0 * 2 4 )/ 3 6 0 0 ;
   int minute = (( int )time)%( 3 6 0 0 * 2 4 ) 6 0 0 / 6 0 ;

   if (days <= 0 &&hours; <= 0 &&minute; <= 0 )
       dateContent= @"0天0小时0分钟" ;
   else
       dateContent=[[ NSString alloc ] initWithFormat : @"%i天%i小时%i分钟" ,days,hours,minute];