In the note, sent in November 2014 ahead of the Thanksgiving holidays, Biden reminded staff that he did not expect nor want anyone to "miss or sacrifice important family obligations for work."
That includes celebrations, such as birthdays, anniversaries or weddings, he writes, as well as time needed to step away from work due to an illness or death in the family.
Biden says his support for staff taking time from work in order to focus on family responsibilities has been an "unwritten rule" since his time in the Senate.
Biden's note in full reads:
To My Wonderful Staff,
I would like to take a moment and make something clear to everyone. I do not expect nor do I want any of you to miss or sacrifice important family obligations for work. Family obligations include but are not limited to family birthdays, anniversaries, weddings, any religious ceremonies such as first communions and bar mitzvahs, graduations, and times of need such as illness or a loss in the family. This is very important to me. In fact, I will go so far as to say that if I find out that you are working with me while missing important family responsibilities, it will disappoint me greatly. This has been an unwritten rule since my days in the Senate.
Thank you all for the hard work.
Biden's focus on prioritizing family despite a demanding workload has been a part of his political career from the beginning. In 1972, weeks after he became the second-youngest man elected to the Senate, Biden's first wife, Neilia, and 1-year-old daughter, Naomi, were killed in a car accident. His two sons, Beau and Hunter, were 3 and 2 at the time and were critically injured.
Despite considering resigning before taking office as Senator of Delaware, Biden was convinced by colleagues to see out his term. Eighteen days after the accident, Biden was sworn in to office from the hospital where his two sons were being treated.
"I felt I should be sworn in with my children today," Biden told reporters from beside Beau's bedside, according to an AP article at the time.
From then on, Biden became known for his commitment to family time, including his four-hour daily commute by train from Wilmington, Delaware, to Washington, D.C., so he could make it home each night to spend the evening with his sons.
"By focusing on my sons, I found my redemption," Biden told students at Yale University's Class Day in 2015.
The president-elect married his now-wife, Jill Biden, in 1977, and the two have one daughter, Ashley, together.
Following the publication of his message on work-life balance in a 2016 Esquire profile and shared by California Gov. Gavin Newsom, Biden further explained his views on work-life balance in a segment for The Tonight Show with Jimmy Fallon.
"There's no such thing as quality time," Biden said. "Every important thing your child will say to you will be off script, as they say, will be at a time when you don't expect it.
"I don't want anybody on my staff feeling an obligation to do something for me when there's something that matters in the family," he added. "There's nothing noble about it."
Biden continued by saying that he follows the same principle, and that he finds the people who work with him are happier and more productive.
As a presidential candidate, Biden outlined policy proposals to further support working parents and their families. In July, he released plans to provide 12 weeks of paid family leave and access to free universal pre-kindergarten programs for 3- and 4-year-olds.
His $775 billion policy plan includes resources to better support and develop the child-care industry; make it easier for families with kids under 5 to afford care through tax credits or subsidies; and calls for expanded access to after-school, weekend and summer care for school-aged children.