Mark Zuckerberg and Priscilla Chan have welcomed their second daughter into the world with a sweet letter posted on Facebook.
The 33-year-old tech billionaire and his pediatrician wife, 32, celebrated the birth of daughter August on Monday with an open letter to her, just like they did upon having their first daughter, Max, in 2015.
While the couple focused on big-picture items like looking toward a future that eradicates disease, advances human potential and promotes universal equality in their letter to Max, the letter to August emphasizes enjoying her childhood.
Mark Zuckerberg and Priscilla Chan share family photo with new babyAug. 29, 201700:31
"The world can be a serious place,'' they wrote. "That's why it's important to make time to go outside and play."
Facebook's Mark Zuckerberg planning 2-month paternity leaveAug. 19, 201701:47
"Childhood is magical,'' the letter continues. "You only get to be a child once, so don't spend it worrying too much about the future. You've got us for that, and we'll do everything we possibly can to make sure the world is a better place for you and all children in your generation."
Zuckerberg announced earlier this month that he is taking two months of paternity leave from his duties as chairman and CEO of Facebook to be with his family after August's birth. He also took two months off after Max was born in November 2015.
Priscilla Chan on $3 billion giveaway, husband Mark Zuckerberg, daughter MaxSept. 22, 201604:53
From the couple's letter to August, it looks like they're already looking forward to all the fun stuff ahead.
"You will be busy when you're older, so I hope you take time to smell all the flowers and put all the leaves you want in your bucket now,'' they wrote. "I hope you read your favorite Dr. Seuss books so many times you start inventing your own stories about the Vipper of Vipp. I hope you ride the carousel with Max until you've tamed every color horse. I hope you run as many laps around our living room and yard as you want.
"And then I hope you take a lot of naps. I hope you're a great sleeper. And I hope even in your dreams you can feel how much we love you."
Follow TODAY.com writer Scott Stump on Twitter.