Particularly in the summer months, many offices adopt a “Casual Friday” or other “Casual Day” during which employees can dress down from their usual professional attire. Often these days are designed to bring a little fun into the workplace, but a mistaken idea about what is appropriate for Casual Day could end up with you cooling your heels at home early or making a horrible first impression on someone that you will be working with. If you have not experienced a casual day in the office before, make sure that you err on the side of caution when you are dressing down.

In many offices, casual day simply means that you do not have to wear a suit (and tie) if you are a man and that you do not have to wear the equivalent level of dress if you are a woman. However, for women, the line is less distinct, since many women wear skirts and blouses on a regular basis, which slightly lowers their level of professional dress already. So before you wear jeans in to work, make sure that this is acceptable and that Casual Day is not really just “ditch your tie and/or heels day.”

Another way that offices may try to make Casual Day fun is by giving it a theme. For example, there might be “Hawaiian Shirt Day” or “Luau Day.” As with any other casual day, be moderate in your interpretation of what is appropriate. Avoid coconut bikinis and other beachwear, including flip flops, unless there has been a precedent set for this type of behavior! Even then, tread lightly so that your behavior is not misinterpreted.

Casual days can be a great way to lighten a mood or reward an office that has really had its nose to the grindstone. Just always be careful to keep propriety in the back of your mind, and think carefully about whether or not you will be participating if the day is not officially sanctioned.