get date of comming days

var query="select * from birthdays where DOB='"+ DateTime.Today.AddDays(15)+"'";
SqlCommand cmd = new SqlCommand(query,cnn);

CREATE FUNCTION [dbo].[GetLatest10Dates1](

@mydate datetime
)
RETURNS
@tbl table (mydate datetime)
AS
BEGIN
 -- Declare the return variable here
 declare @i int =0
while(@i < 15)
begin
insert into @tbl(mydate)
select @mydate+@i
set @i = @i+1
end
 -- Return the result of the function
 RETURN

END

Declare @dat date
set @dat='2013-01-01'

Declare @tbl table (mydate datetime,rn int)
     insert into @tbl(mydate,rn)
(Select *, row_number() over (order by mydate ) as m  From dbo.GetLatest10Dates1(cast(@dat as date)))
select * from @tbl