MARK Zuckerberg has only been a father for a little more than a week, but he’s already earned a World’s Best Dad coffee mug (a really big one). In the past few months, he’s done more to change the game for working fathers — and, by extension, working parents in general — than anyone in recent memory.

Tuesday’s announcement that he and his wife, Dr. Priscilla Chan, would be pledging 99 percent of their Facebook shares, currently worth about $45 billion, for charitable purposes was just the tip of the iceberg.

In August, the 31-year-old debuted his wife’s pregnancy on Facebook, adding that the path to that point had not been an easy one for them as a couple: “We’ve been trying to have a child for a couple of years and have had three miscarriages along the way,” he wrote. “You feel so hopeful when you learn you’re going to have a child. You start imagining who they’ll become and dreaming of hopes for their future. You start making plans, and then they’re gone. It’s a lonely experience.”

There has traditionally been a cone of silence surrounding infertility and miscarriage, and his frank admission was hailed by many as a way of shedding light on a painful topic, making people feel like they weren’t alone. It also signaled just how far we’ve come from the old-school norm that dictated a stifling, stiff upper lip for men.

In November, Facebook unveiled it would be offering four months’ paid baby leave to any full-time employee around the world regardless of gender — a generous package, given that the US is the only industrialized country that does not mandate paid leave for mothers, let alone fathers.

And then Zuckerberg shared that he’d be taking leave — two months of it — when his baby girl arrived. In a culture where it’s often the norm for executives to take very little, if any, leave, this is almost as significant as the policy itself.

“Corporate cultures are top-down. When a top executive actually takes paternity leave, it sends the signal to everyone else in the ranks that it’s OK to do so,” Josh Levs, author of “All In: How Our Work-First Culture Fails Dads, Families and Businesses — And How We Can Fix It Together,” tells The Post.

“There are still Neanderthals out there who don’t get it. Some CEOs believe paternity leave should never exist. They should stop and realize what Facebook knows and has proven: Doing better by your employees is better business.”

Executives — male or female — traditionally didn’t talk much about kids. Mothers may have felt it was in their best interest to hide their personal lives to get along in the Old Boys’ Club. And dads certainly weren’t gushing about it.

But the paradigm has been shifting for a while now, and thank God for that. Because every time a father of Zuckerberg’s position and influence speaks out, it sets in motion a trickle-down effect, letting fathers across the country know it’s OK to talk about stuff — whether it’s the pain of a miscarriage or the need for paternity leave. Every time a dad like Zuckerberg speaks up, it benefits moms as well — issues like paid leave, child care and work-life balance have long been ghettoized as “women’s issues,” discussed by those who experience it but largely ignored by everyone else.

Obviously, most fathers don’t have the power to issue proclamations, institute policies or start foundations. That’s not the point. If this is what we can expect from millennial dads, the future is looking pretty bright.