The fall fashion trend that begins heating up as early as mid-July often runs out of steam by the time the first autumn leaf has turned.
Whether or not that is what will happen to the man's dinner-jacket look - a leading entrant in this year's parade of new styles - is moot. Black tie and tuxedo dressing is already being enthusiastically promoted by the stores. And the retail powers that be may well know what they are doing, for there are signs that acceptance is not in doubt.
A run on 1940s and 1950s white dinner jackets in New York thrift shops this summer evidenced a yearning among frisky young Manhattanites to put extra-sized, shawl-collared, pique sack shapes over their sun dresses.
The formal menswear sported by Julie Andrews in the film ''Victor/Victoria'' has also given a boost to the idea of wearing masculine evening attire. Her boyish haircut is, however, not the advocated coiffure for the woman who would dress like a man. Ralph Lauren and Anne Klein designers Donna Karan and Louis dell'Olio, whose high-fashion versions of men's evening clothes for women are currently being copied by middle-priced manufacturers, see male tailoring as a means of heightening femininity. So their models all had great manes of long flowing hair.
The concept is hardly new (Marlene Dietrich in white tie, top hat, and tails is an often-cited precedent). It tends to crop up periodically, although it no longer causes the furor elicited in the 1960s when Yves Saint Laurent brought out ''Le Smoking'' for women. Similar trouser suits that were literal translations of men's evening gear were in vogue in the 1970s. Designers are being more fanciful this season.
The most prevalent bit of evening haberdashery - the wing collar - knows no restrictions as to time and place. Jeeves would not recognize it. Combined with a bib front, it appears on any number of junior-sized dresses as well as inexpensive cotton blouses with tucked bosoms and deep cuffs. It goes all the way up the price scale, too - as the neckline finish on Oscar de la Renta's costly cashmere knit dresses for the high-salaried female executive.
Sticklers for correctness might be bothered by the black tie that nearly always accompanies this wing collar, but the full-dress wings with the semiformal black tie is just one of many breaks with tradition.
A knee-length black wool dress with elongated lapels of silk faille and a single-button closing low on the hip is among Ralph Lauren's plays on the conventional dinner jacket.
A band-collar tunic of ivory satin with long shirttails over a short and narrow skirt of black velvet is a witty example from Anne Klein of the relaxed stance being taken toward evening tailoring.
There are more exact versions of the man's tuxedo, borrowed in toto, down to the satin stripe on the side of the pants or the skirt. These are worn with a soft shirt and a large, bow tie to ease the hard lines of the rest of the outfit.