If a party is held during traditional mealtimes – 11 AM to 1 PM for lunch, 6 to 8 PM for dinner – then it’s reasonable for guests to expect more than just light nibbles. The exception is a cocktail party, which may be held between the hours of 4 and 8 PM and should be clearly identified as such on the invitation. In fact, to avoid confusion – and embarrassment on both sides – use the invitation to spell out exactly what will be served (e.g., appetizers and cocktails, buffet dinner, barbecue lunch) no matter what kind of party it is.