Sub DerMoinsPrem()
Dim T, i, First
Range(Range("A3"), Cells(Rows.Count, "A").End(xlUp)).Offset(, 3).ClearContents
T = Range(Range("A3"), Cells(Rows.Count, "C").End(xlUp)).Value
First = T(1, 3)
For i = 1 To UBound(T, 1) - LBound(T, 1)
If T(i, 1) <> T(i + 1, 1) Then
Cells(2 + i, "D") = T(i, 3) - First
First = T(i + 1, 3)
End If
Next i
Cells(2 + i, "D") = T(i, 3) - First
Range(Range("A3"), Cells(Rows.Count, "A").End(xlUp)).Offset(, 3).NumberFormat = "0"" t"""
End Sub