After missing two paychecks but no shifts, Logan International Airport TSA local union head Mike Gayzagian said he's glad to see the partial government shutdown end.

“It’s a huge relief, for myself, for the officers,” Gayzagian said, “and we’re hoping that it’s not just a three-week reprieve.”

President Donald Trump on Friday reopened the government for three weeks, setting a Feb. 15 deadline for negotiations for $5.7 billion of funding for his campaign-promised wall along the southern U.S.-Mexico border. He told The Wall Street Journal the chances he and Democrat leaders will come to an agreement are “less than 50-50”.

“I think that’s unfortunate,” said Gayzagian. “I believe they will come to a deal. I think after this experience, what everybody has gone through and public reaction, I believe that they’re going to work it out.”

S&P Global Ratings estimated that the 35-day-long shutdown — the longest in U.S. history — cost about $6 billion, about $30 million more than what Trump wants earmarked for a border wall.

Federal workers, including about 47,000 in Massachusetts, headed to work Monday with a sense of cautious optimism. And at agencies where workers were furloughed, many also faced a month-log backlog made more difficult by the threat of another shutdown.

“We’re back until Feb. 15, but we cannot definitely plan beyond that time because we don’t know that we’re funded,” said Hugh Martinez, an attorney for the Environmental Protection Agency.

Martinez said it may not be possible to catch up on inspections required under the Clean Air Act, “including inspections for accident prevention programs that literally involve materials that have great quantities of extremely hazardous substances."

Martinez said he's worried about the toll this shutdown took on younger workers managing child care costs and student loans, and thinks the shutdown will make it more difficult to keep those workers and attract new ones.

IRS auditor Anthony Moore said the furlough changed the way he feels about working for the federal government.

“It’s making me think, ’Do I want to retire or stay here?’” Moore said. “The job security seems like it’s gone now.”

Last week, Moore took advantage of a food distribution program in Dorchester for furloughed federal workers. He said he’s still worried about making ends meet.

“Even though we’re going to get a check, our back pay, you’ve got to hold onto it because you don’t know what’s going to happen,” he said.