Memorial Day, among other things, marks the unofficial start of summer and that means you can finally break out all those white clothes – especially those white pants and shorts. But act fast. You can only wear them for the next 14 weeks. At least according to an old fashion precept that says white should only be worn between Memorial Day and Labor Day. 

Unlike other enduring rules, like “An apple a day...” which might not really keep the doctor away but is – generally – a healthy idea, or “Look both ways before you cross the street,” which might actually save your life, the rule about only wearing white in the summer is a bit more arbitrary. But that doesn't mean it sprung up arbitrarily.

"Rules exist if there is a larger system in pace in which there is an elite, or there is consensus, that there is one way to do things," said Kathleen McDermott, a fashion historian who teaches at the Mass College of Art and Design.

McDermott says rules governing dress have been around since the enlightenment, a tool used by elite classes to promulgate their culture. In America, that meant White Anglo Saxon Protestants, who began clamping down on everything from hem lines to lapel widths when rules like this one began proliferating here around the turn of the 20th century. 

"Rules about grooming, about dress, about ways to be a proper American, these are coming out of a sense of anxiety on the part of elites in America about the waves of immigration that are coming at that time," said McDermott.

Now we don’t know exactly when this specific rule took hold, though it likely came about around this time. And if it seems like it's origins might be as simple as the fact that wearing white during the summer makes a great deal of sense, McDermott cautions that, when it comes to clothes, intuition can betray you. 

"Practicality is not typically associated with fashion," said McDermott. "So what you might think which is ‘oh, ya know it’s white, it’s comfortable,’ there’s usually a deeper reason behind it."

She points out that the British, who colonized places like India and South Africa, wore tropical whites, and that in the years following the American Revolution white cotton was the world’s single most expensive fabric. 

"It’s not like today where you throw it in the washer and the dryer and you’re white and you’re ready to go," said McDermott. "In order to wear white at certain times in history it took an army of people to wash it, to press it, to starch it, and to start the process all over again after you'd worn it."

Wearing white, she says, has long been an expression of power. But then again, McDermott believes all clothing is about power. 

"That’s one of the reasons why it amuses me when people think fashion is frivolous," she said.

The good news, says McDermott, is that not only did the 1960s bring us the Beatles, the pocket calculator and the first man on the moon, it also brought an end to the notion that a single elite class was writing the script.

"Women, African American, Native American and other groups come to the fore and challenge this idea that there is one, unitary truth about the way to run society," she said. "The idea of clothing rules blows up, too."

So unleash you inner Tom Wolfe. You want to wear white this summer. Have at it. And keep with it well into the fall and winter, too. And if anyone looks at you askance, just remember that when it comes to fashion in the 21st century, there’s really only one rule left: You do you.