It is very discourteous for a guest to be last arrive at least five minutes before the hour set for the dinner. If for some unavoidable reason you cannot arrive on time,telephone the hostess and explain the reason to her. Etiquette only requires that she wait for fifteen minutes before beginning the meal. If it has been impossible for you to notify her and she has starred the meal,go to her,offer apologies,and take your place at the table as quickly as possible