During the Democratic Debate on Wednesday, Sen. Kamala Harris (D-Flailing) spoke about the gender pay gap “in the year of our Lord 2019.” People on Twitter noticed it, and didn’t know how to respond.

Charles Lane, a Washington Post opinion writer, suggested the phrase — a reference to the system of dating years in relation to the birth of Jesus Christ — is “colonialist.”

“‘The Year of our Lord 2019’ is a colonialist concept isn’t it?” Lane tweeted.

"The Year of our Lord 2019" is a colonialist concept isn't it? — Charles Lane (@ChuckLane1) November 21, 2019

Author Caroline Moss thought it was a joke. Then she said it was “so embarrassing!!!!!”

That is so embarrassing!!!!!! And it’s also embarrassing when anyone tweets it — Caroline Moss (@CarolineMoss) November 21, 2019

“I use Year of Our Lord as a joke all the time, but I’m an atheist,” Robyn Pennacchia, a writer for Wonkette and Patheos’s Friendly Atheist blog, chimed in.

I use Year of Our Lord as a joke all the time, but I'm an atheist. — Robyn Pennacchia (@RobynElyse) November 21, 2019

Matt Lewis, a senior columnist at the Daily Beast and political commentator for CNN, noted that Harris said “the year of our Lord” instead of “Common Era.” He asked, “What happened to the party that booed God?”

Yang thinks it's okay for parents to stay home with kids… Kamala says "The year of our Lord" instead of "Common Era." What happened to the party that booed God? — Matt Lewis (@mattklewis) November 21, 2019

Grace Hamilton, a former Hillary Clinton staffer, also thought Harris’s reference to the Christian dating system was a joke. “Why am I not seeing more tweets about Kamala referring to 2019 as the year of our lord? Hands down the best/funniest thing I’ve heard in a debate,” Hamilton tweeted.

https://twitter.com/gracehmltn/status/1197347065312890880

David Greenfield, CEO of the Met Council, merely noted that Kamala’s Christian dating reference “may be the most religious statement of the [Democratic Debate].”

“Year of our Lord 2019.” That may be most religious statement of the #DemocraticDebate @KamalaHarris — David G. Greenfield (@NYCGreenfield) November 21, 2019

Roman Catholic New Yorker Ryan James Girdusky tweeted, “Thank you [Kamala Harris], but that’s not going to win you the religious black vote.”

The year of our lord 2019… thank you @KamalaHarris, but that's still not going to win you the religious black vote #DemocraticDebate — Ryan James Girdusky (@RyanGirdusky) November 21, 2019

In all seriousness, the suggestion that “the year of our Lord 2019” is colonialist or a joke reveals just how post-Christian America has become. Love it or hate it, the entire dating system reflects Christianity. While some try to substitute the phrase with “Common Era,” they still navigate the study of history in terms of two periods, before and after a point at which some medieval scholar wrongly thought Jesus was born.

The birth of Jesus was monumental in the history of the world. Jesus’ Resurrection is arguably the most pivotal moment in history, as it spawned the Christian faith and that faith revolutionized morality, helped lay the foundation for science, and emphasized the value of every human being. The historian Tom Holland — no Christian — has recently published the book Dominion: How the Christian Revolution Remade the World. His book helps explain how Christianity changed the way people see the world, even though most people don’t recognize it.

The “Before Christ/Anno Domini” dating system is imperfect, and so are the “Before Common Era/ After Common Era” phrases with which secularists wish to replace it.

Kamala Harris unwittingly revealed the Christian roots of the modern dating system, and post-Christian Americans didn’t know what to do about it.

Follow Tyler O’Neil, the author of this article, on Twitter at @Tyler2ONeil.