Sunday is International Transgender Day of Visibility, observed around the world to bring attention to a population that’s often ignored, disparaged or victimized.

Here are things to know about the day.

WHAT IS IT?

The “day” is Sunday, but celebrations and educational events designed to bring attention to transgender people are occurring for several days around March 31.

Events were scheduled around the world and include panels and speakers in Cincinnati and Atlanta, marches in Melbourne, Florida and Philadelphia, and an inclusive roller derby league’s game on New York’s Long Island. A picnic is planned in the English town of Hitchin.

Perhaps the highest profile U.S. event is a rally scheduled for Sunday on the National Mall in Washington, D.C.

Major buildings and landmarks across the U.S. will be lit up in pink, white and light blue to mark the day. Last year, those lit included New York’s One World Trade Center and Niagara Falls.

HOW DID IT BEGIN?

Rachel Crandall-Crocker, the executive director and co-founder of Transgender Michigan, organized the first day in 2009.

“I think that once a person understands us, it’s hard to discriminate against us,” she said in an interview. “I created it because I wanted a time that we don’t have to be so lonely. I wanted a day that we’re all together all over the world as one community. And that’s exactly what we are.”

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It was designed as a contrast to Transgender Day of Remembrance, which is held annually on Nov. 20 to honor the memory of of transgender people who were killed in anti-transgender violence.

Crandall-Crocker selected the day at the end of March to give it space from the day of remembrance and Pride Month in June, which celebrates all types of LGBTQ+ people.

She plans to take part in a rally in Lansing, Michigan.

WHY IS IT IMPORTANT?

Transgender people have become more visible in public life in the U.S. and elsewhere.

There also has been a backlash from conservatives officials. At least 11 states have adopted policies barring people from using the bathrooms aligning with their gender in schools or other public buildings, 25 have bans on transgender women and/or girls competing in sports for women or girls and more than 20 have adopted bans on gender-affirming health care for minors. Some of the policies have been put on hold by courts.

Nico Lang, author of “American Teenager: How Trans Kids are Surviving Hate and Finding Joy in a Turbulent Era,” which is scheduled to be published later this year, said it’s important to find happiness even amid the political tumult.

“I feel like we as people — all of us queer people, trans people — are trying to assert our humanity right now,” said Lang, who uses they/them pronouns.

They said the day of visibility is powerful because it’s not just on social media but also in real life with rallies and potluck meals.

“It’s just us living our lives,” they said.