declare @t table (Id int, Value char(5))
insert into @t
select '1','09:01' union
select '1','12:05' union
select '2','08:04' union
select '2','17:09' union
select '3','99888'

select * from @t
select id,stuff((select ','+rtrim(value) 
from @t 
where id=a.id for xml path('')
),1,1,'') as [values]
from (select distinct id from @t) a