Problem with datatypes

[JensAttermeyer]

I have a Problem with a storedprocedure and datatype conversion. If have the following storedprocedure:

ALTER PROCEDURE [dbo].[spGoodsMovement02] @IDbName sysname AS DECLARE @Text nvarchar(max) IF EXISTS(SELECT * FROM sys.databases where name = @IDbName) BEGIN SET @text = N'SELECT TOP 1000 CAST(CONVERT(nchar, lb.Datum, 104) AS DATETIME) AS dateMovement, lb.products_id AS productId, lb.products_model AS productsModel, lb.products_ean AS productsEan, lb.orders_id AS ordersId, o.ID AS orderID, SUM(lb.Bewegung) AS movement, AVG(lb.Bestand) AS stock, pd.products_name AS productsName FROM [' + @IDbName + '].[dbo].[Lager_Bewegungen] AS lb INNER JOIN [' + @IDbName + '].[dbo].[Products_Description] AS pd ON lb.products_id = pd.products_id LEFT OUTER JOIN [' + @IDbName + '].[dbo].[Orders] AS o ON o.orders_id = lb.orders_id WHERE (lb.orders_id > 0) GROUP BY CAST(CONVERT(nchar, lb.Datum, 104) AS DATETIME), lb.products_id, lb.products_model, lb.products_ean, pd.products_name, lb.orders_id, o.ID HAVING (SUM(lb.Bewegung) <> 0) ORDER BY dateMovement DESC,2,3,4,5,6,7' EXEC (@Text) END PRINT 'NO DATABASE EXISTS'

If I call this storedprocedure in SQL Server Management Studio with a correct parameter for IDbName everything is ok and i get a result. If i call the procedure from my meteor app with Sql.sp() and the correct parameters i get the following error: "The conversion of a nvarchar data type to a datetime data type resulted in an out-of-range value." Has anybody an idee what is wrong?