O posibila solutie MS Access

Query sql_1: 

CREATE TABLE ZileNelucratoare (DataCalendaristica DATETIME PRIMARY KEY) 

Query sql_2:

INSERT INTO ZileNelucratoare VALUES ('2007-01-01');

Query sql_3:

INSERT INTO ZileNelucratoare VALUES ('2007-01-02');

Query sql_4:

INSERT INTO ZileNelucratoare VALUES ('2007-02-08'); 

Query sql_5:

CREATE TABLE ZileConcediuConsumate  ( LunaZi DATETIME PRIMARY KEY , NrZileConcediuConsumate INT NOT NULL) 

'0=zi lucratoare / 1=zi nelucratoare
Public Function EsteZiNelucratoare(dt As Date) As Byte 'VB Byte = Int8
    If DatePart("w", dt, vbSunday, vbFirstJan1) = 7 Or DatePart("w", dt, vbSunday, vbFirstJan1) = 1 Then
        EsteZiNelucratoare = 1
    ElseIf IsNull(DLookup("DataCalendaristica", "ZileNelucratoare", "DataCalendaristica = #" & Format(dt, "yyyy-MM-dd") & "# ")) = False Then
        EsteZiNelucratoare = 1
    Else
        EsteZiNelucratoare = 0
    End If
End Function

Public Sub ZileConcediu(dt_start As Date, nr_zile As Long)   'insereaza inregistrari in tabela
    CurrentDb.Execute "DELETE FROM ZileConcediuConsumate"
   
    Dim luna_curenta As Long, i As Long, zile_lunare_concediu_consumate As Long
    luna_curenta = Month(dt_start)
    i = -1
    zile_lunare_concediu_consumate = 0
   
    While nr_zile > 0
        i = i + 1
        Dim dt_curenta As Date, sql As String
        dt_curenta = DateAdd("d", i, dt_start)
        If (luna_curenta <> Month(dt_curenta)) Then
            sql = "INSERT INTO ZileConcediuConsumate VALUES( #" & Format(dt_curenta, "yyyy-MM-dd") & "#" & "," & zile_lunare_concediu_consumate & " )"
            CurrentDb.Execute sql
            luna_curenta = Month(dt_curenta)
            zile_lunare_concediu_consumate = 0
        End If
       
        If EsteZiNelucratoare(dt_curenta) = 0 Then
            'Debug.Print dt_curenta, zile_lunare_concediu_consumate
            zile_lunare_concediu_consumate = zile_lunare_concediu_consumate + 1
            nr_zile = nr_zile - 1
        End If
    Wend
    sql = "INSERT INTO ZileConcediuConsumate VALUES( #" & Format(dt_curenta, "yyyy-MM-dd") & "#" & "," & zile_lunare_concediu_consumate & " )"
    CurrentDb.Execute sql
End Sub

Exemplu utilizare:

[1] din VBA se apeleaza procedura cu parametrii doriti:

Call ZileConcediu ("2007-01-21" , 38 ) 'procedura insereaza in ZileConcediuConsumate inregistrarile dorite

[2] din SQL se interogheaza tabela  ZileConcediuConsumate

SELECT *

FROM ZileConcediuConsumate