''' <summary>

''' MessageBox.Show(saison("19/07/2008"))

''' </summary>

''' <param name="UneDate"></param>

''' <returns="season"</returns>

''' <remarks></remarks>

Function saison(ByVal UneDate As String) As String
Dim num As Int32 = 0 
Dim z As Date
Dim season As String = String.Empty 
Try

If Date.TryParse(UneDate, z) Then

num = z.DayOfYear
Select Case num 
Case Is < 1
season = "error"


MsgBox(num)
Case Is < 81 
If num > 0 Then

season = "hiver"

End If
Case Is < 173 
If num > 80 Then

season = "printemps"

End If
Case Is < 265 
If num > 172 Then

season = "été"

End If
Case Is < 356 
If num > 264 Then

season = "automne"

End If
Case Is < 367 
If num > 355 Then

season = "hiver"

End If

Case Else

season = "error"

End Select

Else

season = "error"

End If
Catch ex As Exception 
Debug.Fail(ex.Message)

End Try
Return season 
End Function

Function DateSaison(ByVal Y As Double, ByVal K As Integer) As String

' Le code est une adaptation du codage en QuickBasic vers VB2008.

' Le site originel se trouve l'adresse : http://sites.rapidus.net/algauthi/intro.htm

' Y : Annee

' K : 0 3 selon la saison

' 0 : EQUINOXE DE PRINTEMPS

' 1 : SOLSTICE D'ETE

' 2 : EQUINOXE D'AUTOMNE

' 3 : SOLSTICE D'HIVER

' Paramtres

Dim Y1, JD, T, RAD, L, M, C, OME, AP, TEST, COR, Z, F, A, X, B, D, E, DayDec, MN, FRAC, Day, Minute, Heure As Double

Dim Mois As String

'Calcul jour

Y1 = Y / 1000
Select Case KCase 0 
JD = 1721139.2855 + 365.2421376 * Y + 0.067919 * Y1 ^ 2 - 0.0027879 * Y1 ^ 3
Case 1 
JD = 1721233.2486 + 365.2417284 * Y - 0.053018 * Y1 ^ 2 + 0.009332 * Y1 ^ 3
Case 2 
JD = 1721325.6978 + 365.2425055 * Y - 0.126689 * Y1 ^ 2 + 0.0019401 * Y1 ^ 3
Case 3 
JD = 1721414.392 + 365.2428898 * Y - 0.010965 * Y1 ^ 2 - 0.0084885 * Y1 ^ 3

End Select

RAD = Math.PI / 180

Do

T = (JD - 2415020) / 36525

'GEOMETRIC MEAN doubleITUDE

L = 279.69668 + (36000.76892 * T) + 0.0003025 * T ^ 2

'SUN MEAN ANOMALIE

M = (358.47583 + (35999.04975 * T) - 0.00015 * T ^ 2 - 0.0000033 * T ^ 3) / 360

M = (M - Math.Floor(M)) * 360

'EQUATION AU CENTRE

C = (1.91946 - 0.004789 * T - 0.000014 * T ^ 2) * Math.Sin(M * RAD) + (0.020094 - 0.0001 * T) * Math.Sin(M * 2) + (0.000293 * Math.Sin(M * 3))

'TRUE LONGITUDE DU SOLEIL

OME = (259.18 - 1934.142 * T) / 360

OME = (OME - Math.Floor(OME)) * 360 * RAD

AP = (L + C - 0.00569 - 0.00479 * Math.Sin(OME)) / 360

AP = (AP - Math.Floor(AP)) * 360

'CORRECTION

TEST = JD

COR = 58 * Math.Sin((K * 90 - AP) * RAD)

JD = JD + COR
Loop While JD - TEST > 0.001 
JD = JD + 0.5

Z = Math.Floor(JD)

If Z < 2299161 Then

A = Z

Else

X = Math.Floor((Z - 1867216.25) / 36524.25)

A = Z + 1 + X - Math.Floor(X / 4)

End If

B = A + 1524

C = Math.Floor((B - 122.1) / 365.25)

D = Math.Floor(365.25 * C)

E = Math.Floor((B - D) / 30.6001)

F = JD - Z

DayDec = B - D - Math.Floor(30.6001 * E) + F

If E < 13.5 Then

MN = E - 1

Else

MN = E - 13

End If

Mois = vbNullString
Select Case MN 
Case 3
Mois = "MARS"

Case 6 
Mois = "JUIN"
Case 9 
Mois = "SEPTEMBRE"
Case 12 
Mois = "DECEMBRE"

End Select

FRAC = DayDec - Math.Floor(DayDec)

Day = Math.Floor(DayDec)

Heure = Math.Floor(FRAC * 24)

Minute = (FRAC * 24 - Heure) * 60

DateSaison = Day & " " & Mois & " " & Heure & "H" & Math.Floor(Minute) & "MIN"

End Function