Last fall, when the American Federation of Teachers endorsed him for president, Barack Obama spoke to a crowd of 3,000 union members and promised that "we will change education in this country; and we will bring about a better future for our children..."

One way to build that better future, Obama has said, is to increase the number of hours children spend in school, both by lengthening the days themselves and by shortening vacations to extend the school year.

But now, as President Obama pushes for more hours in school, some of his staunchest supporters are moving in the other direction, seeking to adopt four-day school weeks as a way to avoid pay cuts and firings in the face of crumbling state budgets.

In order to save everyone's job, teachers' union organizers in many states and school districts are advocating payless furloughs for all employees -- getting four days' pay for four days' work.

But critics say the teachers are putting their own priorities above the students they're supposed to be nurturing, and that payless furloughs will cost the kids services and class time.

In Hawaii, where the Department of Education has to cut $468 million over the next two years, the State Teachers Association, which represents 13,000 public school teachers, has agreed to the creation of "Furlough Fridays." 

Rather than accept layoffs, the teachers have decided to take 17 Fridays off. That means 170,800 students will be out of school on Fridays, and teachers will have to try to cover the instructional minutes for the year in 163 days instead of the usual 180.

"I was really shocked, going 'What are they thinking. Are they insane'?" said Kristie Charron, an elementary school parent. "How are they (the students) going to learn?"

The president of the Teachers Association, Wil Okabe, said he isn't happy with the agreement, but that "Furlough Fridays" will cause the least disruption to the public school system. And he placed the blame for the tough decision on the state's legislators.

"The Board of Education and the Hawaii State Teachers Association should never have been put in this position," Okabe said in a written statement. "Our children and students should not have been forced to miss class days. The state should have maintained a commitment to our children and funded their education at the appropriate level and provided them the 180 days of instructional time they deserve."

On the first Furlough Friday, October 23 -- concerned parents are planning to rally at the Hawaii state Capitol.

"As a parent I just didn't think it could happen. We thought we were protected by federal laws," said Debbie Schatz, co-president of the Parent Teacher Student Association at Aikahi Elementary School.

But the number of days in a school year is determined by the individual states, not the federal government. In Idaho, the school year is 170 days, 10 fewer than most states. Others, like Colorado, Delaware and Michigan, dictate the number of hours -- not days -- in a school year.

And since the length of the school year is decided by states and school districts, the teachers' unions have a great deal of bargaining power in making the decisions.

Other school districts using furloughs to save money this year are in Georgia, North Carolina, New Mexico, Florida and California. And other unions, too, are winning furloughs over layoffs. In the Los Angeles School District, 1,100 bus drivers recently agreed to take six furlough days, leaving parents scrambling to figure out how to get their children to school on the days the buses don't run.

"Furloughs are a way of sharing the suffering equally," said Ed Muir, deputy director of research at the American Federation of Teachers, which has more than 1.4 million members.

"There's nothing that you can do that isn't going to hurt the students. You can do layoffs. You can do furloughs. You're going to increase the class size, taking away instructional time, one way or another," he said.

But critics say there are real losers when teachers take furloughs: the students, who miss valuable time in the classroom. And they say there's another way to meet drastic budgets: fire some bad teachers.

Frederick Hess, director of education policy studies at the American Enterprise Institute, said school officials should be using the economic downturn as an opportunity to consolidate what he says is an overpopulated teacher workforce.

"One good thing about rough patches is that they provide the motivation and cover to make difficult personnel choices," Hess said.

Since 2000, he said, school districts nationwide have hired teachers at twice the rate that they have added new students.

"It's disturbing that rather than addressing this directly, school teachers and school districts are trying to dance around the real issue," Hess said. "Furloughs are a result of small-minded, timid management."

Muir said many AFT unions, including ones in St. Louis and Detroit, are developing measures, like peer reviews, to weed out ineffective teachers. But he said many districts don't have policies on how to deal with those teachers. He also said that peer reviews and layoffs should not be used as a mechanism for dealing with budget cuts. "Due process is a guarantee of a process, not of an outcome," he said.

Muir said unions are doing the best they can in the face of difficult decisions. "When there isn't enough money, there isn't enough money," he said. "There's no good way out of a crisis this bad."

But critics say there's a bad way out of a bad crisis: four-day work weeks and shorter school years.

There are other victims, too. Working parents who are suffering financially will have tough decisions to make on furlough days: whether to pay for child care, skip work or pay for programs that are being created by local service organizations. Some parents in Hawaii are even considering "renting" schools on furlough days and paying the teachers to staff them.

With the Obama administration advocating tougher testing and higher academic standards, critics say, it's ironic that some of Obama's staunchest supporters, the teachers' unions, are putting up roadblocks in his way.

When asked whether there's a growing divide between what the unions are doing by shortening the school week and what the president is advocating, the AFT's associate director of public affairs, John See, said his office was too busy to answer the question.

On further questioning, he said his office is developing a policy to deal with inquiries from Fox News and FOXNews.com.