South-central Idaho’s Valley School District will join the growing number of schools operating on a four-day calendar.

The district will go to the four-day schedule when the 2014-15 school year opens Aug. 20, the Twin Falls Times-News reported this week.

The move comes even after district voters approved a two-year, $600,000 supplemental levy on May 20.

In 2013-14, 40 of Idaho’s 115 public school districts and nine charter schools operated on a four-day calendar. In 2007-08, before the Great Recession, 14 districts and three charter schools used a four-day calendar.