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