Getting consecutive dates in SQL Server 2012 with CTE - sql-server

Question

I have to assign color codes for one specific room alternating between two codes for the year in Microsoft SQL Server. The unique field is each individual date of the calendar.
So sample rows would look like as follows.
weekDay colorName RoomNum
2017-01-01 Blue 100
2017-01-02 Red 100
Color codes need assigned for each week alternating between the 2 colors from Monday (being the beginning of the week) through Sunday counted as the end of the week. So starting Monday January 2, 2017 I would need the following pattern to continue through the next calendar year so the end of 2018.
2017-01-02 Red 100
2017-01-03 Red 100
2017-01-04 Red 100
2017-01-05 Red 100
2017-01-06 Red 100
2017-01-07 Red 100
2017-01-08 Red 100
2017-01-09 Blue 100
2017-01-10 Blue 100
2017-01-11 Blue 100
2017-01-12 Blue 100
2017-01-13 Blue 100
2017-01-14 Blue 100
2017-01-15 Blue 100
2017-01-16 Red 100
.
.
.
I have the following CTE but it assigns 6 days the first week, then assigns 14 days every week after not seven day intervals starting each Monday through Sunday. What am I doing wrong? Thanks!
DECLARE #tableTest TABLE (weekDay datetime, colorName varchar(50), roomNum int);
DEClARE #begindate datetime = '01/02/17';
declare #enddate datetime = '12/31/18';
;with
N0 as (SELECT 1 as n UNION ALL SELECT 1)
,N1 as (SELECT 1 as n FROM N0 t1, N0 t2)
,N2 as (SELECT 1 as n FROM N1 t1, N1 t2)
,N3 as (SELECT 1 as n FROM N2 t1, N2 t2)
,N4 as (SELECT 1 as n FROM N3 t1, N3 t2)
,N5 as (SELECT 1 as n FROM N4 t1, N4 t2)
,N6 as (SELECT 1 as n FROM N5 t1, N5 t2)
,nums as (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 1)) as num FROM N6)
INSERT #tableTest (weekDay, roomNum)
SELECT DATEADD(day,num-1,#begindate) as thedate, 100
FROM nums
WHERE num <= DATEDIFF(day,#begindate,#enddate) + 1
;with weekNumber as (
SELECT weekDay, colorName, roomNum, (DATEPART(ww, weekDay) / 2) % 2 as schedule FROM #tableTest
)
UPDATE weekNumber
SET colorName = CASE WHEN weekNumber.schedule = 0 THEN 'Red' ELSE 'Blue' END
SELECT * FROM #tableTest

Answer 1

You're doing division AND modulo, which is causing you to double the "width" of the modulo, if that terminology makes sense to you. : )
In other words, instead of doing modulo against 1, 2, 3, 4 etc..
You're doing modulo against 1, 1.5, 2, 2.5, 3, etc. Get it?
Anyway, the solution is to change your final update to this:
;with weekNumber as (
SELECT weekDay, colorName, roomNum, (DATEPART(ww, weekDay)) % 2 as schedule FROM #tableTest
)
UPDATE weekNumber
SET colorName = CASE WHEN weekNumber.schedule = 0 THEN 'Red' ELSE 'Blue' END