Ceres Unified is on the cusp of 13,500 students spread between 20 plus campuses.

In terms of overall size, there are larger school districts among the 1,018 districts statewide based on enrollment.

Travel about 160 miles to the southeast and you will come across Big Sur Unified School District. It is in a relatively remote and rugged coastal area of southern Monterey County.

If they did not have a charter school with 101 students authorized under their district umbrella, Big Sur would be the 1,011th largest school district out of 1,018 California districts.

It’s non-chartered school — Pacific Valley — has an impressive 3:1 student ratio.

But it comes with a big caveat. It’s a K-12 campus with just nine students.

It is also unique among California school district for another reason besides being small. Students go to school only four days a week, Monday through Thursday. There are periodically Friday school days, but not often.

There is only one other school district in California the state has allowed to have a four-day school schedule. That’s Leggett Valley Unified of the Eel River in Mendocino County. Compared to Big Sur Unified, it’s a big district with four schools and 75 students.

Other districts — all in remote areas of California — applied for exceptions to the state’s five-day requirement.

That requirement in a year’s time comes to 36,000 minutes for kindergarten, 50,400 minutes for first through third grade, 54,000 minutes for fourth through eighth grade, and 64,800 minutes for high school students It translates into 180 school days a year.

The two districts meet the minutes by extending the Monday through Thursday school schedule. In the case of high school students in Leggett Unified, they start class at 8:15 a.m. and are dismissed at 4:15 p.m. That pencils out to an eight-hour day.

The other districts granted permission by the state to go to four days of instruction either did do so and later dropped it or opted not to implement it after all.

Why this has relevance is simple. There is an emerging trend to go to four-day-a-week instruction. It is taking place not because of academic reasons, but due to the national teacher shortage.

The carrot the school districts are dangling in front of teachers is a four-day work week that offers them more personal freedom with three-day weekends.

Anyone knows the amount of hours a family member or friend that teaches invests away from the classroom in order to be an effective teacher, it is highly likely that extra days off won’t really be extra days off.

The four-day school week has caught on fairly big elsewhere. There are 876 districts in 26 states this school year on four-day schedules. That’s up from 650 in 220.

In Oregon, about a third of the districts are four days a week. The lion’s share is in remote areas.

And the switch wasn’t to attract more teacher applicants but the fact long travel time to athletic competitions that are commonplace in remote areas.

Games — which are scheduled primarily  on Fridays — meant student-athletes, cheerleaders and band members were out of school for most of the day while they traveled long distances to contests.

In Colorado, 69 percent of the districts have four-day-a-week schedules.

Missouri this year has 146 school districts — a quarter of all schools — on four-day a week scheduled as opposed to 119 last year. One of the districts that switched this year to four days is in Independence. That district has 14,000 students.

Independence administrators report a surge in applications for teaching positions. It is a trend that has occurred elsewhere.

The argument of why it is happening, of course, has everything to do with wanting flexibility on the teacher applicants’ part. It has nothing to do with better pay, better work environment, better support, or even better schools.

That doesn’t mean four-day schools aren’t — or can’t be — better schools.

It’s just that the latest trend of larger school districts going all in on four days is risky.

Back in 1975, Mesa Verde High opened in the San Juan Unified School District in eastern Sacramento County to serve the Citrus Heights community. It was designed as a year-round school meaning classrooms were clustered around a “hub” room that teachers shared given there were multiple tracks of students using the same classrooms.

The school was designed for year round education due to explosive growth in Citrus Heights. Two of the nearby elementary schools were already on year round schedules.

Teachers and families liked the flexibility it gave for scheduling vacations. One biggie was the ability of families into skiing who were on the right track could have the slopes in the nearby Sierra almost all to themselves without missing school for a three-week stretch in the depth of winter.

It proved problematic for those students in sports and other extra-curricular activities.

Eventually, Mesa Verde went to a traditional school schedule as there was limited enthusiasm for it in the community and well as in the teaching profession

The point Mesa Verde’s experience has when it comes to four-day-a-week schools is simple.

They had applicants from teachers who liked the idea. But far from every potential teacher who could apply was smitten.

That would seem a move — predicated on seeking a long-term answer to the teacher shortage by cutting school days by 20 percent instead of focusing on compensation and support services — is limited at best.

Clearly, the underlying problems for snaring teachers aren’t being addressed. That means the issues responsible for the teacher shortage  aren’t eliminated or even reduced.

Yes, it works in remote school districts because they are what they are — remote school districts. They have a different lifestyle.

Perhaps a larger district having a school or two that are open enrollment for those districtwide that prefer a four-day schedule would be  effective.

But given research so far, going all in is more than dangerous.

Oregon State University associate professor Paul Thompson has conducted extensive research on four-day schools. He noted nine out of 10 are in rural areas. The rest are in the suburbs and urban areas.

Thompson noted:

• It offers students, administrators, and students more flexibility

• Most teachers use the extra day to prep or grade papers even though they may do it from home.

• It reduces the need for substitute teachers as personal needs such as medical appointments can be scheduled on Fridays.

Thompson notes that there is anecdotal evidence that teacher applicants and retention are up in four-day schools but there is no conclusive research to verify that over the long-haul.

RAND research has showed districts save just under 5 percent of the operating costs with four days of school. Keep in mind that is not staffing costs which is close to 85 percent of most school budgets.

There are potentially serious drawbacks academically.

While there isn’t adequate research to make solid conclusions, at some schools that have switched there is a drop in testing scores in math and language arts. It should be noted they are in states that haven’t stuck to the minimum instructional minutes as California has.

A lot of people with jobs, especially among the lower income, would need to secure childcare.

Even with schools in Independence, Missouri offering $30 daycare on Fridays, that is not affordable for many families.

Yes, four-day school weeks work for some. But if leaders want to really bump up the number of qualified teacher applicants, they need to not rely on short-term gimmicks and concentrate on the tough — and real core — issues.

And by that it means compensation, safer schools, support services, and a school environment that is committed to students excelling.

This column is the opinion of Dennis Wyatt, and does not necessarily represent the opinions of The Courier or 209 Multimedia.