Maybe something like this would work.

SELECT COL1, COL2, NEW_COLUMN
FROM TABLE
CROSS APPLY (VALUES('COL3', CAST( COL3 AS varchar(100))),
       ('COL4', CAST( COL4 AS varchar(100))),
       ('COL5',...

This should be efficient as it reads the table only once.

WITH ClockCounts AS(
  SELECT COUNT(*)   AS ClockIn ,
    COUNT(EndTime) AS ClockOut
  FROM...

Even simpler. You're basically trying to query the current month for the day before.

DECLARE @StartDate date = DATEADD(mm, DATEDIFF( mm, 0, GETDATE() - 1), 0);
DECLARE...

Wild idea:
Why don't you simply update the table instead of deleting and re-inserting?

Actually, ROUND uses 3 parameters. The third parameter indicates if it needs to truncate or round.
There's a difference on how FLOOR and ROUND work with negatives.
I explain...

You also want to use  QUOTENAME() to handle complex names for your columns or objects.

DECLARE @Field_suffix char(1);
DECLARE @sql varchar(MAX);

SET @Field_suffix = '1';

Try this:

DECLARE @sql nvarchar(max)
SELECT @sql = N'SELECT H.UserID' + CHAR(10)
  + STUFF(( SELECT CHAR(10) + CHAR(9) + ',ISNULL( NULLIF( H.' + QUOTENAME(COLUMN_NAME) + ',...

Could you be missing the ROWS clause in the OVER()?

DECLARE @MaxRecords int = 500;

WITH MyLimits
AS
(
SELECT SUM(COUNT(colz.OBJECT_ID)) OVER( ORDER...