Evening weddings are the most elegant type. Whether you are the bride, the groom, or a guest, you will want to look your sharpest for the occasion. This is what you need to know to select appropriate attire for an 8pm wedding.
A wedding that starts at 8pm is almost always going to be formal. At the minimum black tie (or the ambiguous "black tie optional"), or if it is a winter wedding, it may even be white tie, which is the most formal wedding of all. It is up to the bride and groom to determine how formal they want their wedding to be and then to let their guests know with a notation on the invitation stating either "Black tie" or "White tie". If you are having a city chic cocktail wedding which has a late start, you could use a notation such as "Cocktail attire" to give your guests an idea of what to expect and how to dress.
If the 8pm wedding is black tie, the gentlemen all wear tuxedos. For those who want a more modern take on black tie attire, a straight tie can be worn instead of the traditional bow tie. Around the holidays, it would also be appropriate for the male guests (or the groom, for that matter) to wear a bow tie in a tartan rather than the standard black bow tie. The rest of the tuxedo would remain the same as usual.
The bride at a black tie wedding should wear a very fancy wedding gown and lots of sparkling accessories. This would be an appropriate type of wedding for a heavily embellished silk satin gown with a full ballskirt and a long train. There is very little which would be too ornate for such a wedding. She will want to fully accessorize her bridal gown with a crystal tiara, and a breathtaking set of Swarovski crystal bridal jewelry including a necklace, earrings, and bracelets.
Dressing for an 8pm wedding is actually the most challenging for the wedding guests. The attire for the bride and groom is a little more clear; for the female wedding guests, there is such a range of choices that picking the right attire can be bewildering. Hopefully, the invitation gave you a clue as to what type of attire is expected, but if not, you have to take your cue from the late hour of the affair and assume that it is formal. When in doubt, there is no shame in asking the bride or her mother if the wedding will be black tie, white tie, or what have you. Here is a tip: if the invitation or your hosts say that the wedding is black tie optional or black tie requested, wear black tie. It will always look the best for the occasion.
For the female wedding guests, long dresses or very dressy cocktail dresses are appropriate for an 8pm wedding, as long as it is not white tie. If you opt for a short cocktail dress over a floor length gown, it needs to be very fancy, ie, a dressy fabric, special embellishments, the works. One thing to avoid is a cocktail dress which is too sexy. That hot little number which was perfect for New Year's Eve may be inappropriate for a wedding guest; Remember that you never want to draw attention away from the bride! When the wedding is white tie, the female guests must wear floor length gowns, and long gloves are also expected.
One you have found a beautiful fancy dress to wear to the 8pm wedding, it is time to add the accessories which will make your outfit spectacular. A wedding guest would certainly not wear a tiara, but a sprinkling of hairpins or a jeweled clip in your hair would be a gorgeous detail. This is also your chance to wear lots of sparkly jewelry, such as a fabulous pair of chandelier earrings and a few Swarovski crystal bracelets. In the winter months, feel free to layer on a luxe fur stole (real or faux, your choice). Before you know it, you will find yourself ready to go and shine at the 8pm wedding.