Sub MAJ()
Dim R As Range, dest, source, d As Object, i&
Set R = [A1].CurrentRegion.Resize(, 3)
dest = R 'matrice, plus rapide
source = [E1].CurrentRegion.Resize(, 3) 'matrice, plus rapide
'---mémorisation des dates sources---
Set d = CreateObject("Scripting.Dictionary")
For i = 1 To UBound(source)
d(source(i, 1)) = source(i, 3)
Next
'---remplissage du tableau dest---
For i = 1 To UBound(dest)
dest(i, 3) = d(dest(i, 1))
Next
'---restitution---
R = dest
End Sub