Gaines has declared it to be "Real Women's Day."
"A few months ago, during Women's History Month, I noticed a common theme," she noted in a recent post on X. "That theme was that in places where we were supposed to be honoring trailblazing women, we were honoring men who are claiming the identity of a woman."
As an example, she included ESPN's segment on swimmer Will Thomas, a man who says he is a woman named "Lia."
"They honored his persistence and triumph through adversity and what his national title in the 500 freestyle means and how he's a pioneer for women's sports," Gaines recalled.
She also mentioned that Hershey's featured Zac Johnstone, a man who claims to be a woman named "Fae," as part of their promotional campaign for the limited-edition chocolate bars called "HER for SHE" in recognition of International Women's Day.
"This is when I started to think to myself, 'We need a day to honor real women' -- you know, women with XX chromosomes," Gaines explained.
She settled on October 10th because it is the 10th day of the 10th month, which in Roman numerals is XX.
"If you took fifth-grade biology, then you know XX is the female chromosomes," said Gaines.
She then shared that she has tried (unsuccessfully) to get websites and publications on board.
"Every single one of them declined it because they said it was too controversial," the activist relayed. "So, I'm asking and encouraging you to stand with me and all other real women on October 10th in recognizing this day as Real Women's Day."
The petition, available on the website for The Riley Gaines Center at the Leadership Institute, states, "Real Women's Day should be recognized, not only to celebrate womanhood, but to serve as a crucial reminder to keep women's spaces available only to real women."
Gaines has been on a national tour with Independent Women's Voice to push for legislation that defines the term "woman" and keeps locker rooms and bathrooms sex specific.
"Women are being erased, so it's time that our voices are heard," Gaines contends.