Sub test2()
Dim p As Range, m1 As Date, m2 As Date
Dim x As Long, y As Long
With Sheets("Origine")
Set p = .Range("A2", .Cells(.Rows.Count, 1).End(xlUp))
End With
m1 = Application.Min(p)
m2 = Application.Max(p)
'Première ligne contenant m1
x = p.Find(m1, Cells(p.Rows.Count, 1), xlValues, xlWhole, 1, 1, 0).Row
'Dernière ligne contenant m2
y = p.Find(m2, Cells(p.Rows.Count, 1), xlValues, xlWhole, 1, 2, 0).Row
End Sub