Sub essai()
Dim f2 As Worksheet, fc As Worksheet
Dim d2 As Long
Dim c As Range
Dim idx As Variant 'doit rester variant
Set f2 = Sheets("1.2")
Set fc = Sheets("Calendrier")
d2 = CLng(f2.Cells(2, 3).Formula)
idx = Application.Match(d2, fc.Range("E3:E2284"), 0)
If Not IsError(idx) Then
Set c = fc.Range("E3:E2284").Cells(idx, 1)
MsgBox "La date est la " & idx & " ème de la plage de recherche " & vbCrLf & "la cellule correspondantes est la cellule " & c.Address
End If
End Sub