A partial government shutdown took effect at midnight after lawmakers on Friday failed to reach a deal to keep several key agencies funded. The shutdown was over President Trump’s demand for funding for a wall along the U.S.-Mexico border.

Any hope of a solution fizzled at about 8:30 p.m. Friday, when both the House and the Senate had adjourned with no solution in sight. Lawmakers are slated to return to Capitol Hill around noon Saturday to resume talks.

The shutdown comes days before Christmas and has the potential to last much longer.

This is the third shutdown in two years of Republican majority in Washington.

President Trump predicted earlier Friday that it could drag on for a “very long time.”

Trump was already supposed to have left for Mar-a-Lago, but he postponed the trip to the so-called "Winter White House" due to the shutdown. First Lady Melania Trump and their son, Barron, have already left without him.

Here’s what to know:

1. Nine federal departments and several smaller agencies ran out of funding, and their doors are now shut.

2. Roughly 320,000 federal workers are now on furlough.

3. Another 420,000 federal workers that are considered too vital will have to work without pay.

4. Entitlement programs such as the Department of Veterans Affairs, Social Security, Medicare, Medicaid, and food stamps are all part of “mandatory spending” and are slated to keep going.

5. Airports will continue to function during the holiday travel season — but 55,000 Transportation Security Administration employees and 55,000 Customs and Border Patrol agents will have to work without pay. Federal law enforcement agents and correctional officers also will work without pay.

6. The U.S. Postal Service is not affected by any government shutdown because it's an independent agency.

7. While special counsel Robert Mueller’s investigation is under the purview of the Department of Justice, it will not be affected by any shutdown since it has its own permanent source of funding.

8. The National Park Service said this week that parks “will remain as accessible as possible,” in the same way as during a three-day government shutdown in January. However, services that require staffing and maintenance such as campgrounds and full-service restrooms will not be operating.

9. The Departments of Agriculture, Commerce, Homeland Security, Housing and Urban Development, Interior, Justice, State, Transportation, and Treasury are all affected.

10. What about space? About 95 percent of NASA employees won't be able to go to work under a government shutdown, though there are "excepted" employees responsible for keeping NASA people and property safe who continue to work.