MS Sql Server Pivot with dates, Sql Server

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CREATE TABLE CustTable (IDNbr INT IDENTITY(1,1) PRIMARY KEY, CustName VARCHAR(30));

CREATE TABLE IDTable (ID INT IDENTITY(1,1) PRIMARY KEY, BalDate DATE,  Balance DECIMAL(10,2), IDNbr INT);

INSERT INTO CustTable (CustName) VALUES  ('John Doe'), ('Jane Foo');

INSERT INTO IDTable (BalDate, Balance,IDNbr ) VALUES 
('2018-09-01', 10.01, 1),
('2018-09-02', 10.02, 1),
('2018-09-02', 10.02, 1),
('2018-09-01', 10.03, 2),
('2018-09-02', 10.04, 2);

DECLARE @year INT = 2018;
DECLARE @month INT = 9;

DECLARE @Dates NVARCHAR(max);

SELECT @Dates = CONCAT(@Dates + ', ', QUOTENAME(BalDate)) 
FROM IDTable
WHERE YEAR(BalDate) = @year
  AND MONTH(BalDate) = @month 
GROUP BY BalDate
ORDER BY BalDate;

DECLARE @DynSql NVARCHAR(max); 
SET @DynSql = 'SELECT *
FROM
(
  SELECT a1.IDNbr, a2.[CustName] as [Name], a1.BalDate, a1.Balance 
  FROM IDTable a1 
  INNER JOIN CustTable a2 ON (a1.IDNbr = a2.IDNbr)
  WHERE MONTH(a1.BalDate) = @month 
  AND YEAR(a1.BalDate) = @year
) as src
PIVOT (
  SUM(Balance) 
  FOR BalDate IN ('+ @Dates +') 
) pvt';

DECLARE @Params NVARCHAR(500) = N'@year INT, @month INT';

-- SELECT @DynSql AS DynSql;
EXECUTE sp_executesql @DynSql, @Params, @year = @year, @month = @month;

View schema
Execution time: 0,03 sec, rows selected: 8, rows affected: 7, absolute service time: 0,19 sec