Sub process()
Dim Source As Variant
With Sheets("défaut")
For Each Cell In .Range("A2:A" & .Range("A" & .Cells.Rows.Count).End(xlUp).Row)
Source = Sheets("processus(" & Day(Cell) & ")").Range("A1").CurrentRegion
Cell.Offset(0, 3).ClearContents
For i = 1 To UBound(Source)
If Cell.Offset(0, 2) = Source(i, 3) And Cell >= Source(i, 1) And Cell <= Source(i, 2) Then
Cell.Offset(0, 3) = Source(i, 4)
Exit For
End If
Next i
Next Cell
End With
Erase Source
End Sub