Although far less widely known and celebrated in the U.S. than Valentine’s Day or Mother’s Day, International Women’s Day is a much more interesting holiday.

It is one of the few truly global holidays, observed in most countries around the world (hence the prominence it gets at the United Nations, that international enclave in the heart of New York City).

Unlike Mother’s Day and Valentine’s Day, IWD is not a romantic or family-oriented holiday. On International Women’s Day, women accept recognition for their hard work and achievements in both the public and private spheres, and gather to advocate for further advancement down the road to full gender equality.

Gender equality looks different depending on where in the world you are located. But at its core is one of the fundamental principles of human rights: that no human being should be discriminated against on the basis of their physical attributes.

Even in the U.S., supposedly a bastion of liberal values, we have a long way to go before we arrive at the goal of gender equality. This is partly a vision problem: there is still a fair amount of confusion over what a society in which men and women were treated equally would look like.

In every society in transition, there is anxiety about change from those who have been benefiting from unearned privilege (in the U.S., that would be white males, especially of the Christian variety). Giving up privilege is hard.

It was good to see Sheryl Sandberg and Adam Grant make the case in The New York Times this week about why gender equality, “in the boardroom and the bedroom,” will make both men and women happier, healthier, more successful and less stressed out.

It was also good to see a group of Afghan men taking the unprecedented step of standing up for women’s human rights in their country by donning burkas themselves—in much the same vein as the “Walk A Mile In Her Shoes” campaign that has men marching together in women’s high heels to protest sexual assault.

Burkas and high heels are very different in intention—the one aimed at completely covering up a woman’s body and face, the other aimed at accentuating and drawing attention to women’s legs—but similar in effect: these are dress codes that hamper women’s ability to stand strong and step out comfortably and confidently into the world.

I know Western women who will argue that they feel more confident wearing their heels, and I’m sure there are Afghan women who prefer to step out in public shielded by their burkas. But this has everything to do with the world in which they operate, dominated by an often hostile, or at least aggressively attentive male gaze. It’s not about their own comfort in their own bodies.

No, we’re not going to get back to the Garden in which Adam and Eve romped about gaily without so much as a fig leaf coming between them and their lovely natural surroundings.

But this International Women’s Day, let’s reaffirm the basic principle that all human beings are created equal and deserve equal human rights, no matter what they look like and no matter where they live—beginning with the right to step out confidently into a affirming, welcoming world.

As U.N. Secretary General Ban Ki-Moon puts it, “To be truly transformative, the post-2015 development agenda must prioritize gender equality and women’s empowerment. The world will never realize 100 per cent of its goals if 50 per cent of its people cannot realize their full potential.”

Amen to that! And as the International Women’s Day 2015 theme says, it’s time to “Make It Happen!”