declare @temp table (D date, X int default 0)
insert into @temp 
  (D)
  values 
  ('01.01.18'),
  ('02.01.18'),
  ('03.01.18'),
  ('04.01.18'),
  ('05.01.18'),
  ('06.01.18')

create table periods (S date, E date)
insert into periods
  values
  ('25.10.17', '05.01.18'),
  ('20.04.16', '30.10.17'),
  ('02.01.18', '05.01.18'),
  ('08.01.18', '09.01.18'),
  ('03.01.18', '10.01.18')

update t
  set X = (select count(*) from periods where t.D between S and E)	
  from @temp t

merge into @temp d
using (
        select t.D, count(1) as cnt
          from @temp t
          join periods p
            on t.d between p.s and p.e
         group by t.d
      ) s
   on (d.d = s.d)
 when matched 
   then update set d.x = s.cnt;