select A.TheDate, B.Value Today, C.Value Yesterday
from (
select TheDate from T1
union
select DateAdd(day, 1, TheDate) from T1
) A
left join T1 B
on A.TheDate=B.TheDate
left join T1 C
on DATEDIFF(day,C.theDate,A.thedate)=1
order by A.TheDate asc