SELECT 
SUM(  TIMESTAMPDIFF(HOUR, xxx.datefrom, xxx.dateto) +24)div 24 AS expr1
FROM
  xxx

create table some (id int auto_increment, idap int, df datetime, dt datetime, primary key(id));
insert into some (idap, df, dt) values 
(1, '14.09.07 10:00',  '14.09.10 10:00')
, (1, '14.09.10 19:00',  '14.09.11 10:00')
, (2, '14.09.05 10:00',  '14.09.12 10:00')
, (2, '14.09.14 19:00',  '14.09.17 10:00')
, (4, '14.09.07 10:00',  '14.09.07 11:00')
, (4, '14.09.10 19:00',  '14.09.10 21:00');

create table bree (i int auto_increment, primary key(i));
insert into bree values (), (), (), (), (), (), (), (), (), (), (), (), (), ();

select idap, count(cnt) as cnt from
(
    select distinct stayday as cnt, idap from
    (
        select 
        idap
        , if ((unix_timestamp(date(d.dt)) -  unix_timestamp(date(d.df)) - 60 * 60 * 24 * (s.i - 1)) >= 0, date(d.df + 10e5 * (s.i - 1)), 0) stayday
        from some d, bree s 
        
    ) t1
    where stayday > 0
) t2
group by 1;

idap	cnt
1	5
2	12
4	2