Private Sub cboReportingDate_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
Dim dtTmp As Date
Cancel = False
On Error GoTo err_baddate
dtTmp = CDate(Me.cboReportingDate)
Me.cboReportingDate = VBA.Format(dtTmp, "dd/mm/yyyy")
On Error GoTo 0
sub_ex:
Exit Sub
err_baddate:
MsgBox "Bad date", vbOKOnly + vbExclamation
Cancel = True
Resume sub_ex
End Sub