with a(id, d) as (  -- здесь должна быть ваша таблица
  select 1, '20151201'  union all
  select 2, '20160926'
) 
, b as (  -- таблица чисел от 1 до 3
  select number as n from master.dbo.spt_values where type='P' and number between 1 and 3
) 

select a.id, dateadd(day, b.n, a.d) as newD 
  from       a
  cross join b
  order by a.id, newD;

create table dbo.ii(i int not null primary key clustered);