Have you ever seen a bride walk down the aisle in a pair of pants? Probably not. On this important day, even the most modern brides and grooms find themselves in classic ensembles not so different from those worn by their counterparts generations ago.

That's because when choosing wedding clothes, couples are guided not only by fashion, romance, and fantasy, but also by tradition and a dose of decorum befitting the event. Wedding etiquette makes wardrobe suggestions based on the time of day and the level of formality.

A daytime celebration is one held before 6 p.m., while an evening wedding is held after 6 or begins a bit before and continues well into the night. The question of formality is less straightforward; it is not a single detail that gives a wedding its style, but all of the elements combined.

For example, an evening event in an ornate, grand ballroom with a seated multi-course dinner and an orchestra calls for equally impressive attire: for the groom, full dress or white tie; for the bride, perhaps a satin gown with a voluminous skirt and long veil. For an afternoon wedding outdoors with pots of wildflowers, food fresh off the grill, and a lively bluegrass band, a smart suit for him and white pique sun dress for her would be charming. In between, there are countless variations. What follows are guidelines for a variety of wedding styles. 

For a formal event -- during the day or evening -- a bride can never go wrong with a long, white dress. 

Strapless dresses are considered formal all the time, however, according to traditional etiquette, a strapless dress is more appropriate for an evening wedding or one that starts during the day and goes into the evening.

As for him, a tuxedo will work for almost any occasion, or your groom has the rare opportunity to wear the distinguished morning suit, with its cutaway jacket, waistcoat, and ascot.

White tie attire is only suitable for a formal evening affair, never during the day.

This pale-pink strapless sheath gains a modicum of modesty with an off-the shoulder jacket; short gloves and a pearl choker adds retro appeal. 

A shorter length dress, whether below or above the knee, is also an acceptable option for a daytime event.

If the event will not go into the evening at all, traditional etiquettes suggests staying away from strapless dresses.

A dress made out of matte jersey is a great all-around option because it can work no matter what time of day for a semiformal or informal wedding. 

The groom's short gray jacket, called a stroller, is worn with striped trousers.

For the bride, the same rules that apply for a semiformal event during the day apply for a semiformal evening event, except for one. Traditional etiquette suggests you keep the shorter length dresses to daytime events only. 

Here, a beaded tulle gown creates a soft silhouette and is a great option for a semiformal event. The organza, lace, and the strapless style of this dress is perfect for evening. 

Today, a tuxedo is appropriate for all but the most informal of affairs for him.

For an informal event during the day, it's bride's choice. Short or long, the choice is more about the fabric. As stated before you can't go wrong with matte jersey for any semiformal or informal event, cotton is another good choice for an informal event. 

Here, the bride wears a column dress with graphic embroidery that is darling and a bit daring -- and the bride can wear this dress again. 

Whatever you decide, just make sure that the dress matches the style of the event. You don't want to be overdressed at your own party.

For the groom, a floral tie, worn with a tan cotton-rayon suit, is a cheerful and fitting accent for a wedding held outdoors on a lovely afternoon.

Again, for an informal event during the day or the evening, it's bride's choice. 

You can never go wrong with a matte-jersey dress like this one. It is flirty and fun, but with a long, full skirt, the bride who wears this will still look like a bride.

You also have the option to throw out tradition with a more casual event. Why not wear a strapless dress with a fuller skirt that falls just above the ankle? 

For the groom, a sleek black suit with a subdued plaid tie is a stylish choice when the sun goes down.