A federal judge just ruled that the U.S. census will go on... through October 31. The Census Bureau had extended the deadline to finish the once-a-decade count of the population, but over the summer Trump administration officials moved that date back a month to September 30. The Trump administration has appealed the judge's ruling.

The battle over the deadline of the census got us curious about what difference a month can really make. Well, it turns out that when the job requires you to count every person in every household in America, every day matters. For a peak behind the curtain, we turned to one of the few men in America who knows the ins and outs of how the Census Bureau pulls it all off.

"Article I, Section II of the US constitution mandates that we count everyone living in the United States," said Jeff Baylor, Director for the U.S. Census Bureau’s New York Region, which includes Massachusetts.

So how does the U.S. Census Bureau do it?

The starting point, said Baylor, is a painstakingly assembled list of every single habitable address in the country.

"Throughout the decade (between censuses) we’re building up that address list to make sure we have every possible location where someone lives or could live," he said.

From there the goal is simple, though not easy: Get an answer — of some sort — as to who is living at every address on the list. The preferred means is to get people to self-report, either by filling out a form mailed to them or responding by phone or online. Baylor said that the best, cheapest way to get the most accurate data. Here in Massachusetts, nearly 69 percent of households have self-reported. But that means about 31 percent have not. And the only way to bridge that gap? Good, old-fashioned people power.

"We probably have about six to eight thousand doorknockers right now in the Commonwealth of Massachusetts out there knocking on doors," said Baylor.

The census can and does rely on what they call administrative data — from places like the IRS or state agencies — to give them clues about whether a given address is likely vacant. In those cases they’ll only visit once to confirm that. Otherwise census workers visit any given address a minimum of six times to try and get a response. Only then will they move on to the next strategy.

"Then we have the ability to talk to a neighbor to get data about a housing unit," said Baylor. "Is it occupied and if so do you know how many people live there?"

Along the way, other methods are employed. Baylor said the census relies on thousands of partners — from elected officials to church leaders — to spread the word and help them meet people where they are. Baylor cites a recent afternoon he spent in Lynn as an example, where census workers from the community spent time at a food distribution sight with tablets, helping folks fill out their census forms.

"And like over a hundred families were enumerated in like a two-hour period,' he said. "These were families that didn’t fill it out online or weren’t opening their doors."

Only after all of those avenues are exhausted will the census bureau turn to an estimation as a last resort — employing something called statistical imputation.

"Basically, looking at data we’ve collected around that particular housing unit — or all the other housing units in the community — to statistically determine what we thing that housing unit looks like," said Baylor.

Baylor said the goal is to rely on statistical imputation for less than 1% of households. Here in Massachusetts, between self-reporting and all that door knocking, 98.7 percent of households have been counted as of Monday. And while that sounds pretty close to 100 percent, there are 20-plus states that currently have a higher response rate than we do.

The Census Bureau also conducts overnight counts of the population experiencing homelessness.

And then, after all that work, there’s more work.

"What we do at the end of the census, once we’re done with data collection is we unduplicate people and households," said Baylor.

Maybe a college student is counted both at their parents’ home and an apartment. Or a person moved in the past few months and filled out a census form at both addresses.

If you have a concern we ask that you err on the side of filling it out again to make sure that everyone living with you gets counted," said Baylor.

Much has been made about the census being crucial to determining things like congressional seats and allocation of federal dollars. And that’s true. But it’s also critical to local officials, businesses and pollsters to make accurate calculations about almost anything having to do with people. The Census Bureau needs to complete their count by October 31, and that means— if you haven’t already — there there’s still time to stand, or go online, and be counted.