Blake Lively celebrates Galentine's Day

— -- Leslie Knope once called it "only the best day of the year."

No, she wasn't talking about Valentine's Day, but Galentine's Day, a day for girlfriends, which is celebrated the day before, on Feb. 13.

Never mind that it was a made-up holiday by a made-up character played by Amy Poehler on "Parks and Recreation," actress Blake Lively went all out for Galentine's Day, hosting an event for L’Oreal Paris for New York Fashion Week with her sister Robyn Lively and mom Elaine.

"I thought, right now, more than ever, it's so great that women are coming together and supporting each other and building each other up," Lively told E! News. "I got a little too involved. I said, I don't really just want to show up. I sort of want to plan it. It's a lot more fun to plan a party when it's not on your dime. I changed the party a bit."

One highlight of the event was a special wall where women got to write what they're worth.

Lively wrote, "I’m worth...my rights, equality, love, respect, kindness, opportunity, inclusion, more sleep, chocolate."

"This is the first time in my lifetime where I have been aware of a woman's worth being questioned. I know it happens all the time everywhere, but I never felt it," explained the actress, who attended the Women's March on Washington last month. "It's made me so much more aware and empathetic to the challenges that women face always because I've been really fortunate. I think it's just so important that we come together and build each other up -- and that we remind women of their value. It's really beautiful to see women come together. It's something I've never seen."

Lively shared some snaps from the event on her Instagram.

She even posted a video of her getting ready for the big night.

And when it was all done, she and her sister put up their feet and wished all gals a "Happy Galentine's Day."

After celebrating her "gals," Lively still had to figure out Valentine's Day with hubby Ryan Reynolds.

With two young daughters at home, "we haven't really planned anything yet," she told E! News.