Você pode usar uma tabela adequada com números, como a tabela master..spt_values como base para a geração do intervalo:
;WITH dates AS (
SELECT DATEADD(DAY,number,CAST('2014-01-01' AS DATE)) d
FROM master..spt_values WHERE TYPE = 'p'
AND number < 366
)
SELECT
Week = DATEPART(WEEK, d),
DayOfWeek = DATENAME(dw, d),
Date = d
FROM dates
WHERE DATENAME(dw, d) IN ('Monday', 'Friday')
-- or use datepart instead as datename might be specific to language
-- WHERE DATEPART(dw, d) IN (2,6)
Saída de amostra:
Week DayOfWeek Date
----------- ------------------------------ ----------
1 Friday 2014-01-03
2 Monday 2014-01-06
2 Friday 2014-01-10
3 Monday 2014-01-13
3 Friday 2014-01-17
4 Monday 2014-01-20
4 Friday 2014-01-24
5 Monday 2014-01-27
5 Friday 2014-01-31
