declare @dtFrom datetime;
declare @dtTo datetime;
declare @diff int;

select 
    @dtFrom = '2010-01-01T00:00:00.000',
    @dtTo = '2010-12-31T00:00:00.000',
    @diff = datediff(day, @dtFrom, @dtTo) + 1;
	
create table #Dates
(
    [Date] datetime not null primary key
);

-- this happily inserts dates exactly between first and last date, no more and no less
insert into #Dates
select top (@diff)
    dateadd(day, row_number() over (order by [object_id]) - 1, @dtFrom)
    from sys.all_columns;
	
select * from #Dates;

drop table #Dates;

INSERT INTO #Dates 
  (
    [Date],
    [SomeValueForDate]
  )
SELECT DATEADD(DAY, @n, [Date]) AS [Date],
       @n AS [SomeValueForDate]
FROM #Dates
WHERE DATEADD(DAY, @n, [Date]) <= @dtTo -- No need to delete data after that

DECLARE @dtFrom DATETIME
DECLARE @dtTo DATETIME
SET @dtFrom = '2010-01-01T00:00:00.000'
SET @dtTo = '2010-12-31T00:00:00.000'

DECLARE @Diff INT
SET @Diff = DATEDIFF(DAY, @dtFrom, @dtTo)

CREATE TABLE
 #Dates
(
 [Date] DATETIME NOT NULL PRIMARY KEY,
 [SomeValueForDate] INT NOT NULL
)

CREATE TABLE #Digits(digit INT NOT NULL PRIMARY KEY);

INSERT INTO #Digits(digit)
VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

SELECT DATEADD( DAY, D3.digit * 100 + D2.digit * 10 + D1.digit , @dtFrom) AS n
FROM 
	#Digits AS D1
	CROSS JOIN #Digits AS D2
	CROSS JOIN #Digits AS D3
WHERE  
	D3.digit * 100 + D2.digit * 10 + D1.digit  <= @Diff
ORDER BY n;

DROP TABLE #Digits
DROP TABLE #Dates