How did our school calendar get that way anyhow? Why this three-month vacation gap in the summer, which has come to be accepted as a normal way to do things?

In fact, it is an archaic custom that harks back to America's agrarian days when the great majority of the population was engaged in agricultural production.Families needed their children at home during the period when crops were sowed, cultivated and harvested.

Today, only a small percentage of Americans are engaged in agriculture. Less than 5 percent of the population, in fact, feeds all of our country and much of the rest of the world.

And that's a good argument for looking at the school calendar and making changes. In other industrialized countries, children spend much more time in school, and when comparisons are made, American students come up way short.

Comparing an American student who has spent 180 days a year in school with a Japanese student who has spent 240 days a year in class - two months more - is like comparing a 12th grader with a ninth grader. Over the 13-year term of the usual public school experience, that means the Japanese student gets several years of academic advantage over the American student. No wonder when the international comparisons are published, the United States comes out with egg on its face.

Time in class, obviously, isn't the only factor that affects the quality of education, but it is at least a compelling consideration.

Extending the school year has become central to restructuring plans in many parts of the country. Several states are seeking additional school days and now Utah has tentatively entered the arena.

Three cheers for the Ogden School District for leading out in Utah. The district's proposal to lengthen the school year by 20 days is a step in the right direction and, hopefully, will set a standard for the rest of the state.

Ogden's would-be innovators are already aware of some of the stumbling blocks to a successful reworking of the school calendar.

They start with money - how to cover the extra school time without a precipitous rise in the budget. If any state knows about the barriers created by a limited income, Utah is the one. We spend less per student than any other state, although our taxpayers make a significant effort - a reality created by large families and the second youngest population, proportionately, of any state in the union. (Only Alaska, a new frontier, has a younger population.)

Public acceptance of a significant change in the school year also could be a deterrent. Old public habits die hard, even when there is no compelling reason to continue them.

Teachers may well resist a lengthening of the school calendar without a concomitant increase in their salaries, as proposed in the Ogden concept. They are uncomfortable with the proposal to allow paraprofessionals to take over their classrooms periodically to save money.

Should the plan succeed in Ogden and go statewide, districts that have schools on year-round schedules would have particular problems extending the school year.

No doubt as Ogden continues to study the proposal, other stumbling blocks will become apparent.

I have faith in the creative ability of Utah's educators to find acceptable solutions - compromises in some instances, no doubt - that will allow children to be in school more days of the year.

To allow the stumbling blocks to become insurmountable obstacles would be to doom Utah to an educational mode as outdated as the family farm.