DEAR MISS MANNERS: A close friend texted to see if my husband and I were available on a certain Saturday, three months out, to celebrate her husband’s milestone birthday. She’s thinking of having a dinner at a downtown restaurant for about five couples. (We’ve done similar events for other milestone birthdays.)

My husband and I disagree on the etiquette of how long we have to let her know if we are free. What’s appropriate?

GENTLE READER: To text her right back, of course. Were you planning to wait to see how you feel the day of the dinner? But perhaps you are confusing this with the save-the-date notification, which applies to events at least six months later and does not require a commitment.

Three months may be borderline, however. If you can truthfully say, “We’re planning a trip around that time, but don’t know the exact dates,” Miss Manners will allow you to do so, provided you also tell your friend when you expect to be able to give her an answer.

And rest assured that if there is a death in the family, or you are invited to the White House for dinner that night, you may cancel.

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