In the 2015-16 school year, 26,881 students attended school only four days a week in Idaho. They accounted for 9 percent of Idaho’s student population. The four-day school calendar has been an unproven experiment — no one can say with certainty whether the schedule helps or hinders student achievement. Most concede the schedule does not save money. Opinions are rampant. Hard statistics are scarce. And the state’s political leaders have done little to find answers.

Data dive: Surprising statistics on four-day schools

An unproven experiment, involving 26,881 Idaho students

Sage and COSSA Academy: Two four-day outliers

Four-day school test scores are inconclusive — but troubling

Preston upholds a decision driven by dollars

A schedule change saves money. Just not much.

‘No time to waste:’ Notus runs at a fast pace

Teachers and students adjust to longer school days

Across rural Idaho, four-day weeks become routine