Equal Pay Day was chosen to show how far into the new year a woman has to work, to earn what her male counterpart did in the previous year.
Back in 1996, women made, on average, 74-percent of what men made. Now, women earn 80-percent.
Sen. Kamala Harris' (D-Calif.)Op-Ed in Teen Vogue says women need to stop playing nice. Harris wrote: "One study found that while half of men negotiated for their salary, only one out of eight women did...so let's encourage women to advocate for themselves in spite of what society may say."
Harris said more companies need to be like San Francisco's Salesforce, which reviews employee salaries and makes adjustments when they find unexplained differences.
In the meantime, a San Francisco supervisor introduced legislation Tuesday that would ban employers from asking job applicants about previous salaries. "If women are asked to disclose their prior salaries, it will continue to exist," San Francisco Board Supervisor Mark Farrell said.
National figures are also sounding out. Ivanka Trump took to Twitter saying: "Equal Pay Day is a reminder that women deserve equal pay for equal work. We must work to close the gender pay gap."
And Facebook Executive Sheryl Sandberg's non-profit, lean.org has launched a national retail campaign called #20percentcounts.
The reasoning behind the campaign is this, if a woman makes 20 percent less than a man, she should pay 20 percent less for the purchases she makes.
Businesses in 25 cities are offering 20 percent discounts or special offers on Tuesday.
Click here for locations of businesses offering discounts for Equal Pay Day.