#define floor(x) ((x*2.0-0.5) Shr 1)
#define pi (4 * Atn(1))

Function Gregorian(db As String) As Integer
    Dim As Integer M, Y, D
    Y = Valint(Left(db,4)) :  M = Valint(Mid(db,6,2)) : D = Valint(Right(db,2))
    Dim As Integer N = (M+9) - Int((M+9)/12) * 12
    Dim As Integer W = Y - Int(N/10)
    Dim As Integer G = 365 * W + Int(W/4) - Int(W/100) + Int(W/400)
    G += Int((N*306+5)/10)+(D-1)
    Return G
End Function

Function Biorhythm(Birthdate As String, Targetdate As String) As String
    'Jagged Array
    Dim As String TextArray(4,2) = {{"up and rising", "peak"}, {"up but falling", "transition"}, {"down and falling", "valley"}, {"down but rising", "transition"}}

    Dim As Integer DaysBetween = Gregorian(Targetdate) - Gregorian(Birthdate)

    Dim As Integer positionP = DaysBetween Mod 23
    Dim As Integer positionE = DaysBetween Mod 28
    Dim As Integer positionM = DaysBetween Mod 33

    'return the positions - just to return something
    Biorhythm = Str(positionP) & "/" & Str(positionE) & "/" & Str(positionM)

    Dim As Integer quadrantP = Int(4 * positionP / 23)
    Dim As Integer quadrantE = Int(4 * positionE / 28)
    Dim As Integer quadrantM = Int(4 * positionM / 33)

    Dim As Single percentageP = Fix(100 * Sin(2 * pi * (positionP / 23)))
    Dim As Single percentageE = Fix(100 * Sin(2 * pi * (positionE / 28)))
    Dim As Single percentageM = Fix(100 * Sin(2 * pi * (positionM / 33)))

    Dim As Single transitionP = Val(Targetdate) + floor((quadrantP + 1) / 4 * 23) - positionP
    Dim As Single transitionE = Val(Targetdate) + floor((quadrantE + 1) / 4 * 28) - positionE
    Dim As Single transitionM = Val(Targetdate) + floor((quadrantM + 1) / 4 * 33) - positionM

    Dim As String textP, textE, textM, Header1Text, Header2Text
    Select Case percentageP
    Case Is > 95
        textP = "Physical day  " & positionP & " : " & "peak"
    Case Is < -95
        textP = "Physical day  " & positionP & " : " & "valley"
    Case -5 To 5
        textP = "Physical day  " & positionP & " : " & "critical transition"
    Case Else
        textP = "Physical day  " & positionP & " : " & percentageP & "% (" & TextArray(quadrantP,0) & ", next " & TextArray(quadrantP,1) & " " & transitionP & ")"
    End Select

    Select Case percentageE
    Case Is > 95
        textE = "Emotional day " & positionE & " : " & "peak"
    Case Is < -95
        textE = "Emotional day " & positionE & " : " & "valley"
    Case -5 To 5
        textE = "Emotional day " & positionE & " : " & "critical transition"
    Case Else
        textE = "Emotional day " & positionE & " : " & percentageE & "% (" & TextArray(quadrantE,0) & ", next " & TextArray(quadrantE,1) & " " & transitionE & ")"
    End Select

    Select Case percentageM
    Case Is > 95
        textM = "Mental day " & positionM & "    : " & "peak"
    Case Is < -95
        textM = "Mental day " & positionM & "    : " & "valley"
    Case -5 To 5
        textM = "Mental day " & positionM & "    : " & "critical transition"
    Case Else
        textM = "Mental day " & positionM & "    : " & percentageM & "% (" & TextArray(quadrantM,0) & ", next " & TextArray(quadrantM,1) & " " & transitionM & ")"
    End Select

    Header1Text = "Born " & Birthdate & ", Target " & Targetdate
    Header2Text = "Day " & DaysBetween

    Print Header1Text
    Print Header2Text
    Print textP
    Print textE
    Print textM
    Print
End Function

Biorhythm("1943-03-09", "1972-07-11")
Biorhythm("1809-02-12", "1863-11-19")   'correct DOB for Abraham Lincoln
Biorhythm("1809-01-12", "1863-11-19")