"I'm going on parental leave for December to be with August and Max, so you'll hear from me a little less. We have a couple more Facebook and philanthropy announcements this year and then I'll see you all in 2018!" Zuckerberg writes on his Facebook page.
This summer, shortly after August was born, Zuckerberg said he would take his paternity leave broken up into two blocks: immediately, and then again in December.
Though Zuckerberg, who is currently worth almost $70 billion according to Forbes, could certainly afford to take the time off regardless of Facebook's paid leave policy, as CEO, he sets the tone for the company.
"At Facebook, we offer four months of maternity and paternity leave because studies show that when working parents take time to be with their newborns, it's good for the entire family. And I'm pretty sure the office will still be standing when I get back," Zuckerberg said in August.
In addition to four months of paid leave for parents, Facebook also offers more than 40 private nursing rooms, educational sessions for new families and fertility services, according to an email from Facebook to CNBC Make It.
However not all employees in America are so lucky. The United States federal government does not legally require paid parental leave. That puts the country behind Estonia, Croatia, Korea, Mexico, Cyprus and dozens of other developed nations, according to data compiled by the Pew Research Center.