"When Max was born, I was on leave for two months, I was always grateful to spend a lot of time with him early in life, our second daughter coming soon and I'm back on a two-month leave," Zuck wrote on his official Facebook account.
Max is Zuck and Chan's first child, born in 2015.
Facebook itself is generous to give birth leave, both for mother or father, in a long time.
"On Facebook we offer four months of maternity leave because studies show that when working parents spend time with their babies, it will be good for the whole family and I'm sure the office will be there when I get back," Zuck said.
During Zuck's leave, the reins of Facebook's leadership are likely to be held by two people with the highest positions there. Namely Chief Operating Officer Sheryl Sandberg and Chief Financial Officer David Wehner.
This year, Facebook is experiencing tremendous growth with its share price jumping more than 40%.
Zuckerberg was getting rich with the estimated last estimate by Forbes for US $ 70.1 billion.