Fairfax County School Superintendent Robert R. Spillane, faced with continuing community and teacher opposition, has withdrawn all proposals to change the number of hours elementary students spend in class next year.

The move represents an unconditional surrender for Spillane, who just a month ago declared the issue of the elementary school schedule important enough "to go to war" with his critics on the School Board, on the Board of Supervisors and in the teachers unions.

"I'm reminded of Kenny Rogers -- you got to know when to hold 'em and know when to fold 'em, and I'm folding them on this one," Spillane told the School Board on Thursday night.

Then, in an unusual bow to one of his chief opponents, he turned to the president of the Fairfax Education Association, who had lobbied against his proposals. "Maureen Daniels, you were absolutely right -- it's time to move on," he told her. "This is the first time we've agreed in a long, long time, and I hope it's not the only time."

Daniels, who has accused Spillane of stubbornly clinging to the issue because of his ego, welcomed his move as a "happy ending" and a chance to concentrate on other items.

"I really am relieved," Daniels said yesterday. "I take him at his word that we need to get on with {running the schools}. I think he saw the political handwriting on the wall, which was that there was no way he was going to salvage this and maintain his credibility as our instructional leader."

For more than a year and a half, Spillane and School Board Chairman Kohann H. Whitney (Centreville) have campaigned to abandon the school system's longstanding practice of closing elementary schools up to 2 1/2 hours early on Mondays.

Spillane and Whitney argued that keeping the county's 72,000 elementary students in school 6 1/2 hours five days a week would add the equivalent of three weeks to the school year.

Teachers complained it would disrupt their one chance each week for uninterrupted, collaborative planning.

Although School Board members unanimously supported the concept in November 1989, an effort to pass a specific proposal failed on a 5 to 5 vote last November, largely because of concern over the $5.9 million price tag.

Spillane, defiantly charging that politics had killed his plan, resurrected it with a lower cost, $3.6 million, in January, but ran into near-universal opposition from the community.

Then, in a partial retreat, he suggested extending Mondays but reducing the other four days of the week so that students would spend six hours in school each day.

While there would be no net increase in class time, Spillane portrayed the idea as an interim step on the way to a uniform 6 1/2-hour school day.

In an interview yesterday, Spillane said he abandoned that idea for three reasons: opposition from Daniels's union and the Fairfax County Council of PTAs, the $1.6 million it would cost in added wages for bus drivers and scheduling difficulties that would force 48 schools to open as late as 9:30 a.m.

He said he remains committed to the concept of the 6 1/2-hour day, but promised board members that he will not propose it again without direction from them.

"I will keep the vision of a restructured day as being critical . . . but I will not bring it up again unless a School Board member brings it up again, and then I'll grab that flag and run with it," he said. "If we can't do it this year, do it next year. If we can't do it next year, do it the year after."

Most board members expressed surprise at the move, and several supporters of extended Mondays said they were sorry Spillane gave up.

"It's an educational loss to many of our children . . . who need that extra exposure to the classroom," said School Board member Armando M. Rodriguez (Mount Vernon). "I know that delay is something that can't be helped, but I also can't help feeling the loss for these children."