Not currently at my desk so the syntax might need correcting, but could you do something like this?

WITH CTE(N) AS (SELECT 1 FROM (VALUES(1),(1),(1),(1),(1),(1),(1),(1),(1),(1))a(N)),

CTE2(N) AS (SELECT 1 FROM CTE x CROSS JOIN CTE y),

CTE3(N) AS (SELECT 1 FROM CTE2 x CROSS JOIN CTE2 y),

CTE4(N) AS (SELECT 1 FROM CTE3 x CROSS JOIN CTE3 y),

CTE5(N) AS (SELECT 1 FROM CTE4 x CROSS JOIN CTE4 y),

CTE6(N) AS (SELECT 0 UNION ALL

SELECT TOP 97199 ROW_NUMBER() OVER(ORDER BY (SELECT NULL))

FROM CTE5),

TALLY(N) AS (SELECT DATEADD(month, N, 0)

FROM CTE6)

SELECT a.N AS recorddate, ISNULL(b.myValue,0) AS myValue

FROM TALLY a

OUTER APPLY (SELECT DATEADD(month, DATEDIFF(month, 0, [recorddate]), 0), SUM([myvalue])

FROM [#a] c

WHERE DATEADD(month, DATEDIFF(month, 0, [recorddate]), 0) = a.N

GROUP BY DATEADD(month, DATEDIFF(month, 0, [recorddate]), 0)

) b(recorddate,myValue)

CROSS APPLY (SELECT MIN(DATEADD(month, DATEDIFF(month, 0, [recorddate]), 0)),

MAX(DATEADD(month, DATEDIFF(month, 0, [recorddate]), 0))

FROM [#a]) d(minDate,maxDate)

WHERE a.N >= d.minDate AND a.N <= d.maxDate;