U.S. government agencies closed during the 35-day partial shutdown began reopening Saturday, two days before the Internal Revenue Service will begin processing 2018 tax filings.

The shutdown ended Friday night, after President Donald Trump signed a three-week spending bill passed by Congress to end the longest government shutdown in U.S. history.

The U.S. Office of Management and Budget sent a memo late Friday to closed federal government departments and agencies to inform them that their divisions were now open and that their employees could return to work. The memo also called on the agencies to "reopen offices in a prompt and orderly manner."

A note "to all IRS employees" on the department's website said employees were expected to report to work "no later than four hours after this announcement is posted on Friday, January 25, 2019, at 9:30 p.m. ET." Beyond that, the post advised employees to "report to work at the beginning of your next scheduled workday."

Other agencies

Some websites of other departments that had been affected by the shutdown — State, Transportation, Agriculture, Justice and Interior — had notices that the departments would be back up and running as soon as possible. The Interior Department, however, still had a video titled "Seasons Greetings from Interior."

Many parks -- from the Virgin Islands National Park to the Mississippi National River and Recreation Area in Minnesota — reopened Saturday, but a statement from Grand Canyon officials said the park, in the southwest U.S. state of Arizona, would not be entirely operational until the end of next week.

In Washington, D.C., the Smithsonian museums and the National Zoo are to reopen Tuesday.

Roughly 800,000 federal employees missed their second consecutive paychecks on Friday. Earlier this week, Congress passed and Trump signed legislation ordering federal agencies to issue back pay to workers "at the earliest date possible." But officials cautioned that it could take several days for federal employees to receive back pay. (VOA)

• A Transportation Security Administration worker hands an ID card back to a flier, Jan. 25, 2019, at Seattle's airport.