How to read default value when data not present in table.

Generate a list of dates within the range required and join that with your table using the ISNULL function to derive your default value.

For example I created some simple sample data like this

CREATE TABLE CP5
(
    aDate date,
    aValue int
)

insert into CP5 values(getdate() - 1,1)
insert into CP5 values(getdate() - 2,2)
insert into CP5 values(getdate() - 3,3)
insert into CP5 values(getdate() - 5,5)
insert into CP5 values(getdate() - 6,7)

Set up my start/end dates as follows

DECLARE @startdate date
SET @startdate = getdate() - 7  -- i.e. 2015-02-24
DECLARE @enddate date
SET @enddate = getdate();       -- i.e. 2015-03-03

I can now use this query to get all of the dates in the range with either a value from the table or 0

WITH q AS
        (
        SELECT  @startdate AS datum
        UNION ALL
        SELECT  DATEADD(dd, 1, datum)
        FROM q WHERE  DATEADD(dd, 1, datum) < @enddate
        )
SELECT  datum, ISNULL(aValue, 0) as aValue
    FROM    q
    LEFT OUTER JOIN CP5 ON q.datum = CP5.aDate

Gives me these results

2015-02-24  0
2015-02-25  7
2015-02-26  5
2015-02-27  0
2015-02-28  3
2015-03-01  2
2015-03-02  1

The idea for the CTE was adapted from the Tip Generating a Sequence in SQL[^] by Manas Bhardwaj (My name also appears next to that tip but I can't take credit for the date sequence bit at all)