DEAR MISS MANNERS: When is it acceptable to specify the ending time of an event?

Generally, if I am inviting guests for dinner, I ask them to please arrive at a certain time, with no ending time given. But for a child’s birthday party, one would invite guests from, say, 2 p.m. to 4 p.m., so parents know when to pick up their children.

If I am hosting a cocktail party, is it acceptable to invite guests from, say, 4 p.m. to 6 p.m., so that it is clear that this is not a dinner party? How about a reception where the venue is only rented for a certain number of hours? What is the rule?

GENTLE READER: Specifying a time for the party on the invitation is fine — so long as you do not intend to enforce it.

Please send your questions to Miss Manners at missmanners.com, by email to [email protected], or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.