The government shutdown is in its fourth week. How many days is that?

The federal government's partial shutdown became the longest in American history on Jan. 12, stretching into its 22nd day to surpass a 21-day record set in 1995. And it's still going.

That means 800,000 federal workers have been furloughed or forced to work without pay, and the loss of government services is affecting millions more.

History suggests that shutdowns resolve when public frustration with inaction begins to boil over. As the shutdown drones on from week to week, people are turning to Google to ask when the government's standstill started and what it means for Americans.

Here are answers to the most-searched questions about the shutdown, according to Google Trends.

How long has the government been shut down?

If you want to know how many days the government has been shut down, here's an up-to-the-minute count from USA TODAY:

Why is the government shutdown happening?

The standstill hinges on President Donald Trump's demands for $5.7 billion to pay for a southern border wall that he promised during his campaign.

Democrats, who control the House, call the wall "ineffective and expensive" and have refused to approve billions for the wall tied to funding legislation.

Trump has refused to approve funding legislation without billions for the wall. Left without funding, parts of the government closed. In all, nine federal departments and smaller agencies have closed their doors.

When did the government shutdown begin?

The partial government shutdown began Saturday, Dec. 22, after last-minute negotiations in Congress failed to end the budget standoff. “We’re very prepared for a long shutdown,” Trump said at the time.

It's the the twenty-first shutdown Americans have endured.

What is a government shutdown?

A government shutdown happens when the House, Senate and president can't agree on a spending plan. Without approved funding, the government has no money to fully operate and parts deemed "non-essential" are closed until a funding agreement is reached.

The federal departments that have been affected in the current shutdown are Homeland Security, Justice, Agriculture, Treasury, State, Interior, Transportation, Commerce, and Housing and Urban Development.

Follow Josh Hafner on Twitter: @joshhafner

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This article originally appeared on USA TODAY: The government shutdown is in its fourth week. How many days is that?