There’s good reason for LGBT families in Nashville and across the country to celebrate this Labor Day.

It’s been 17 years since Congress passed the Family and Medical Leave Act — groundbreaking legislation that allows parents to take unpaid time off from work to care for their children.

But since then, work has changed. So have workers.  What many have been slow to recognize though is the fact that “families” have changed, too.

The Obama administration took a major step in recognizing that change recently, when the U.S. Department of Labor clarified the definition of “son and daughter” under the FMLA. Our interpretation ensures that an employee who assumes the role of caring for a child receives parental rights to family leave regardless of the legal or biological relationship. We’ve done so because the realities of who is a “mother” and who is a “father” — and new, important and responsible concepts of “parenthood” — simply demand it ... at home and at work.

It’s called in loco parentis, a Latin phrase and legal doctrine meaning in the place of a parent. When applied to the new realities of work and family, it means that all employees who have assumed the responsibility for parenting a child, whether they have a biological or legal relationship with the child or not, may be entitled to FMLA leave.

Consider the case of Nazanin Meftah and her partner, Lydia Bañuelos, a lesbian couple in Tucson. Meftah developed medical complications after the birth of the couple’s children in 2007 and 2009. Despite a clear need and obvious relationship to the children, Bañuelos was denied unpaid leave both times by her employer. She wasn’t able to care for the kids because she was not a biological parent or legal guardian.

I had the chance to meet Ms. Meftah, and her story is sadly as common as it is compelling. The Williams Institute at the University of California, Los Angeles, School of Law estimates that more than 100,000 children growing up with same-sex parents could benefit from this simple but important action.

The Labor Department’s interpretation of the FMLA makes clear that children can get the support and care they need from the people who love them and are responsible for them. This is certainly a win for LGBT families, and it recognizes the importance of a partner who shares in the parenting of a child in a same-sex relationship. But it’s also a win for “Tia” (Spanish for aunt) who steps in to care for her young nephew when his mother has been called to active military duty, or a grandmother who takes responsibility for her grandchild.

We know that family-friendly policies and laws like the FMLA aren’t “niceties” but rather necessities that contribute to the well-being of all families and a better bottom line for employers.

That’s worth celebrating this Labor Day . . . and no further interpretation of that is required.