Const DTS_START_YEAR = 1970
Const DTS_START_MNTH = 1
Const DTS_START_DAY = 1
Const DTS_STRAT_RBY = 2

'===============================\
'   RENVOI LE MARQUAGE ACTUEL    \
'=================================\
Public Function NowStamp() As Long
    NowStamp = DateToStamp(Now)
End Function

'===============================\
'  CONVERTI UN MARQUAGE EN DATE  \
'=================================\
Public Function StampToDate(ByVal Value As Long) As String
    Dim dys   As Integer
    Dim scs   As Integer
    Dim mns   As Integer
    Dim hrs   As Integer
    Dim d     As Integer
    Dim m     As Integer
    Dim b     As Integer
    Dim n     As Integer
    Dim Y     As Integer
    Dim mxd() As Byte
    '--------------------------
    ReDim mxd(1 To 12)
    '--------------------------
    mxd(1) = 31
    mxd(2) = 28
    mxd(3) = 31
    mxd(4) = 30
    mxd(5) = 31
    mxd(6) = 30
    mxd(7) = 31
    mxd(8) = 31
    mxd(9) = 30
    mxd(10) = 31
    mxd(11) = 30
    mxd(12) = 31
    '--------------------------
    scs = (Value Mod 60)
    mns = (Value \ 60) Mod 60
    hrs = (Value \ 3600) Mod 24
    dys = (Value \ 86400)
    '--------------------------
    b = DTS_STRAT_RBY
    d = DTS_START_DAY
    m = DTS_START_MNTH
    Y = DTS_START_YEAR
    While dys > 0
        d = d + 1
        n = mxd(m)
        dys = dys - 1
        If (b = 0) And (m = 2) Then n = (n + 1)
        If (d > n) Then
            d = 1
            m = m + 1
            If (m > 12) Then
                m = 1
                b = b - 1
                Y = Y + 1
                If (b < 0) Then b = 3
            End If
        End If
    Wend
    '--------------------------
    StampToDate = DateSerial(Y, m, d) & " " & TimeSerial(hrs, mns, scs)
    '--------------------------
End Function

'================================\
'  CONVERTI UNE DATE EN MARQUAGE  \
'==================================\
Public Function DateToStamp(ByVal Value As Date) As Long
    Dim scs   As Integer
    Dim mns   As Integer
    Dim hrs   As Integer
    Dim dow   As Integer
    Dim yrs   As Integer
    Dim mth   As Integer
    Dim dys   As Integer
    Dim d     As Integer
    Dim m     As Integer
    Dim b     As Integer
    Dim n     As Integer
    Dim Y     As Integer
    Dim mxd() As Byte
    '--------------------------
    ReDim mxd(1 To 12)
    '--------------------------
    mxd(1) = 31
    mxd(2) = 28
    mxd(3) = 31
    mxd(4) = 30
    mxd(5) = 31
    mxd(6) = 30
    mxd(7) = 31
    mxd(8) = 31
    mxd(9) = 30
    mxd(10) = 31
    mxd(11) = 30
    mxd(12) = 31
    '--------------------------
    scs = Second(Value)
    mns = Minute(Value)
    hrs = Hour(Value)
    dow = Day(Value)
    mth = Month(Value)
    yrs = Year(Value)
    If yrs <= 1969 Then Err.Raise 380
    If yrs >= 2040 Then Err.Raise 380
    '--------------------------
    b = DTS_STRAT_RBY
    d = DTS_START_DAY
    m = DTS_START_MNTH
    Y = DTS_START_YEAR
    Do
        If (Y = yrs) And (m = mth) And (d = dow) Then Exit Do
        d = d + 1
        n = mxd(m)
        dys = dys + 1
        If (b = 0) And (m = 2) Then n = (n + 1)
        If (d > n) Then
            d = 1
            m = m + 1
            If (m > 12) Then
                m = 1
                b = b - 1
                Y = Y + 1
                If (b < 0) Then b = 3
            End If
        End If
    Loop
    '--------------------------
    DateToStamp = scs + (mns * 60&) + (hrs * 3600&) + (dys * 86400)
    '--------------------------
End Function

$timestamp = 1143410400;
$date = '2006/03/27';
echo $myDate = date ('d-m-Y', $timestamp); // transforme un timestamp $timestamp en une date de type dd-mm-yyy.
echo $myTimestamp = strtotime ($date); // transforme une date VALIDE en timestamp

DECLARE @Variable AS DATETIME
DECLARE @VariableTS AS TIMESTAMP

SET @Variable = getdate()

SET @VariableTS = CONVERT(TIMESTAMP, @Variable);

SELECT 
 CONVERT(DATETIME, @VariableTS) AS VariableEnDate,
 @VariableTS AS VariableEnTS
;

Public Function StampToDate(ByVal vnStamp As Long) As Date
    StampToDate = DateAdd("s", vnStamp, #1/1/1970#)
End Function
Public Function DateToStamp(ByVal vdDate As Date) As Long
    DateToStamp = DateDiff("s", #1/1/1970#, vdDate)
End Function