Doubt SQL Query Business Days

Renan, this is the code that receives the period to issue as values. From these values are generated the months and calculated the number of working days for each monthly period.

-- código #1 v3
--> informe a data inicial e final (formato dd/mm/aaaa)
declare @DataInicial date, @DataFinal date;
set @DataInicial= convert(date, '1/4/2017', 103);
set @DataFinal= convert(date, '30/6/2017', 103);

-- garante sequência nos parâmetros
IF @DataInicial > @DataFinal
  goto _FIM;

--
with cteData as (
SELECT @DataInicial as InícioMês,
      case when eomonth(@DataInicial) > @DataFinal
           then @DataFinal 
           else eomonth(@DataInicial) end as FinalMês
union all
SELECT dateadd(day, +1, FinalMês), 
       case when eomonth(dateadd(day, +1, FinalMês)) > @DataFinal
            then @DataFinal 
            else eomonth(dateadd(day, +1, FinalMês)) end
  from cteData
  where FinalMês < @DataFinal
)
SELECT year(InícioMês) as Ano, month(InícioMês) as Mês,
       dbo.dias_uteis (InícioMês, FinalMês) as [Dias úteis]
  from cteData;

_FIM:
go

The code uses the eomonth () function, available from the 2012 release of SQL Server.

Version 3 of the code also works for cases where the review period does not involve full months. For example, one can search from 5/3/2017 to 20/6/2017 or even 10/2/2017 to 20/2/2017.

I did not really understand this function that you said you have, I tried to do it as simply as possible.

SELECT YEAR(dias_uteis) AS 'Ano',
MONTH(dias_uteis) AS 'Mes',
dias_uteis AS 'Dias Uteis'
FROM dbo
WHERE dias_uteis BETWEEN '01-04-2017' AND '30-06-2017'
GROUP BY MONTH(dias_uteis);

Select dbo.dias_uteis('01-04-2017','30-04-2017') abril,
       dbo.dias_uteis('01-05-2017','31-05-2017') maio,
       dbo.dias_uteis('01-06-2017','30-06-2017') junho

I think this is