Error in custom SQL report; want to convert to SWQL

patriot

I have a custom SQL report that generates an error in 2020.2.6 - probably because it is from an older database schema. Can anyone help with the error message at the beginning and also convert it to SWQL? Appreciate it.

Error executing SQL: Operand type clash: datetime2 is incompatible with numeric
Query:

SELECT TOP 10000 CONVERT(DATETIME, LTRIM(MONTH(DATETIME)) + '/01/' + LTRIM(YEAR(DATETIME)), 101) AS SummaryMonth
      , Nodes.NodeID AS NodeID
      , Nodes.CustomerName AS CustomerName
      , Nodes.Caption AS NodeName
      , Nodes.IP_Address AS IP_Address
      , AVG(ResponseTime.Availability) AS AVERAGE_of_Availability
      , (
            SELECT AVG(ResponseTime.Availability)
            FROM ResponseTime
            INNER JOIN Nodes ON Nodes.NodeID = ResponseTime.NodeID
            WHERE Nodes.CustomerName = 'ACME Bird Seed'
                  AND DATETIME BETWEEN CONVERT(NUMERIC(9, 4), DATEADD(month, - 3, GETDATE()))
                        AND CONVERT(NUMERIC(9, 4), GETDATE())
            ) AS CustomerAverage
FROM Nodes
INNER JOIN ResponseTime ON (Nodes.NodeID = ResponseTime.NodeID)
WHERE (
            DATETIME BETWEEN CONVERT(NUMERIC(9, 4), DATEADD(month, - 3, GETDATE()))
                  AND CONVERT(NUMERIC(9, 4), GETDATE())
            )
      AND ((Nodes.CustomerName = 'ACME Bird Seed'))
GROUP BY CONVERT(DATETIME, LTRIM(MONTH(DATETIME)) + '/01/' + LTRIM(YEAR(DATETIME)), 101)
      , Nodes.NodeID
      , Nodes.CustomerName
      , Nodes.Caption
      , Nodes.IP_Address
ORDER BY SummaryMonth ASC
      , 2 ASC

KMSigma.SWI

Isn't this a duplicate thread of Need a report on Customer device availability - Report Lab - The Orion Platform - THWACK (solarwinds.com)?

Myself and others are already working on this.  Please do not post duplicate threads as it fractures the workload.