To Mark Zuckerberg, Thursday is more than the 12th birthday of his wildly popular social media network. It's #friendsday. 

Zuckerberg declared Thursday the second annual #friendsday, writing in a post on his page last month that it's important to recognize the growth of Facebook's community. The site had about 1.6 billion monthly active users as of Dec. 31.

"The acts of friendship, love and kindness we all share on Facebook are changing the world every day in ways we can't fully measure," Zuckerberg wrote on Jan. 12. "Sometimes they just make people in our lives feel a bit more loved. Sometimes friendship becomes a force that sets us on a different path in life. Sometimes friendship moves the world."

Facebook's #friendsday comes just before the start of Amnesty International's Friendship Week, which this year is aimed at building connections with people in other countries in light of the ongoing Syrian refugee crisis. If you're celebrating either event — or just looking for some kind words to send a pal in need — read on for a collection of sayings from Goodreads and BrainyQuote:

"The language of friendship is not words but meanings." ― Henry David Thoreau

"She is a friend of mind. She gather me, man. The pieces I am, she gather them and give them back to me in all the right order. It's good, you know, when you got a woman who is a friend of your mind." ― Toni Morrison

"There is nothing better than a friend, unless it is a friend with chocolate." ― Linda Grayson

"The friend who holds your hand and says the wrong thing is made of dearer stuff than the one who stays away." ― Barbara Kingsolver

“The better part of one's life consists of his friendships.” ― Abraham Lincoln

"Friendship is the hardest thing in the world to explain. It’s not something you learn in school. But if you haven’t learned the meaning of friendship, you really haven’t learned anything." ― Muhammad Ali

“The antidote for fifty enemies is one friend.” ― Aristotle

“A friend is someone who knows all about you and still loves you.” ― Elbert Hubbard

"The only way to have a friend is to be one." ― Ralph Waldo Emerson

"Some people go to priests; others to poetry; I to my friends." ― Virginia Woolf

“Life is an awful, ugly place to not have a best friend.” ― Sarah Dessen

“The pain of parting is nothing to the joy of meeting again.” ― Charles Dickens

“A friend is one who walks in when others walk out.” ― Walter Winchell

“A friend can tell you things you don't want to tell yourself.” ― Frances Ward Weller

"A true friend freely, advises justly, assists readily, adventures boldly, takes all patiently, defends courageously, and continues a friend unchangeably." ― William Penn