Public Sub PreviousCouponDateBasisTest()
    'Confirms that the Basis is irrelevant to the Excel COUPPCD function.

    'Note: You must establish a Reference to atpvbaen.xls within Excel for this to work.

    Const FmDate = #1/1/1991#
    Const ToDate = #1/1/1998#

    Dim datSettl As Date, datMatur As Date, intFreqLog2%, intFreq%, intBasis%, varResZero, varResOthr

    For datSettl = FmDate To ToDate
        DoEvents
        If Day(datSettl) = 5 Then datSettl = datSettl + 20
        If Day(datSettl) = 1 Then Debug.Print Now, datSettl

        For datMatur = datSettl + 1 To ToDate
            If Day(datMatur) = 5 Then datMatur = datMatur + 20
            
            For intFreqLog2 = 0 To 2
                intFreq = 2 ^ intFreqLog2
                varResZero = COUPPCD(datSettl, datMatur, intFreq, 0)

                For intBasis = 1 To 4
                    varResOthr = COUPPCD(datSettl, datMatur, intFreq, intBasis)
                    If varResOthr <> varResZero Then
                        Debug.Print datSettl, datMatur, intFreq, intBasis, CDate(varResZero), CDate(varResOthr)
                    End If
                Next intBasis
            Next intFreqLog2
        Next datMatur
    Next datSettl

End Sub