IsHoliday

' Verifica se a data é um feriado (municipal, estadual ou nacional, baseado em Salvador/BA)
' @author Roger Pestana
' @date 17/oct/2021
Function IsHoliday(ByVal target_date As String, ByVal reference_year As Integer) As Boolean
        Dim found, holidays_unfixed_index As Integer
        Dim holidays, holiday_carnival, holiday_goodfriday, holiday_corpuschristi As Variant

        ' Valores-base
        Const BASE_YEAR = 2021
        Const MAX_HOLIDAYS_YEAR = 2030
        found = False
        holidays_unfixed_index = reference_year Mod BASE_YEAR

        ' Lista de feriados definida de 2021 a 2030
        holidays = Array("01/01", "21/04", "01/05", "24/06", "02/07", "07/09", "12/10", "02/11", "15/11", "08/12", "25/12")
        holiday_carnival = Array("16/02/2021", "01/03/2022", "21/02/2023", "13/02/2024", "04/03/2025", "17/02/2026", "09/02/2027", "29/02/2028", "13/02/2029", "05/03/2030")
        holiday_goodfriday = Array("02/04/2021", "15/04/2022", "07/04/2023", "29/04/2024", "18/04/2025", "03/04/2026", "26/03/2027", "14/04/2028", "30/03/2029", "19/04/2030")
        holiday_corpuschristi = Array("03/06/2021", "16/06/2022", "08/06/2023", "30/05/2024", "19/06/2025", "04/06/2026", "27/05/2027", "15/06/2028", "31/05/2029", "20/06/2030")

        ' Define os feriados móveis do ano
        If holidays_unfixed_index <= (MAX_HOLIDAYS_YEAR - BASE_YEAR) Then
                holidays_unfixed_list = Array(holiday_carnival(holidays_unfixed_index), holiday_goodfriday(holidays_unfixed_index), holiday_corpuschristi(holidays_unfixed_index))
        End If

        ' Feriados fixos
        For i = 0 To (UBound(holidays) - LBound(holidays))
                If DateValue(holidays(i) & "/" & reference_year) = DateValue(target_date) Then
                        found = True
                        Exit For
                End If
        Next i

        ' Feriados móveis
        If reference_year >= BASE_YEAR Then
                If DateValue(holidays_unfixed_list(0)) = DateValue(target_date) _
                        Or DateValue(holidays_unfixed_list(1)) = DateValue(target_date) _
                        Or DateValue(holidays_unfixed_list(2)) = DateValue(target_date) _
                Then _
                        found = True
        End If

        IsHoliday = found
End Function