Clark County Public Schools joined a long list of districts in central Kentucky canceling classes for the Aug. 21 solar eclipse.

Clark schools Superintendent Paul Christy announced the closure Monday.

“After careful consideration and consultation with entities that have an in-depth understanding of the magnitude of the upcoming solar eclipse, I have decided to cancel school and all school activities prior to 4 p.m. on Monday, Aug. 21,” Christy said in a statement posted to the district’s Facebook page.

Christy said he initially planned to extend the day by 20 minutes, but after more research decided canceling was the safest course of action for students.

“After further investigation and discussion with folks who are much more informed about the eclipse than I was, I decided that extending for 20 minutes would not put us past the time of the eclipse,” he said. “That would in turn put kids on the road in buses in the dark. Of course, our kids are on the bus in the dark sometimes, but not with the phenomenon of an eclipse happening outside the window.” Christy said extending the day any further would create issues with after-school childcare or scheduling for parents and would leave teachers with classrooms of as many as 25 students to ensure are wearing their glasses properly.

And, while Christy said he never makes decisions about closing based on other district, he learned Clark was the only central Kentucky district in session that day.

“I like to think I make good decisions, but when the surrounding counties are all canceling school that day and you aren’t, that makes you rethink your decision,” he said. Neighboring Madison and Montgomery counties, along with Pulaski and Mercer county schools, elected to have non-traditional instruction days, meaning students will have assignments to be completed at home. Estill and Harrison counties are closed, but staff will still work. Bourbon County issued a cancellation of classes and school-related activities until 4 p.m.

In Fayette County, the board of education voted to switch a scheduled day off in October to give students Aug. 21 off. Other school districts closing included Rowan County, Corbin and Williamsburg Independent Schools. Knox, Franklin and Lincoln county schools will extend the instruction day.

Christy said the Clark County Board of Education would discuss in the future whether to schedule a make-up day.

“We have a schedule that has some make-up days built in at the end of the year,” he said. “But it’s something the board will have to discuss.”

He said classroom instruction involving the eclipse will take place before the event, to remind students of the significance of the eclipse and how to a watch it safely.

“We still want to use this as a teachable moment,” he said. “It’s going to be a long time before anyone gets to experience this again, so we don’t want our students to miss out on the instruction that goes along with that.”

Christy wants parents and guardians to visit eclipse2017.nasa.gov/safety for reliable tips regarding how to safely view the eclipse with children, and encourages them to have discussions with their children and any caregivers about how the safety tips.

NASA advises that a total solar eclipse is about as bright as the moon — and just as safe to look at. But, the sun at any other time is dangerously bright and should only be viewed through solar filters.

According to the site, “The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as “eclipse glasses” or hand-held solar viewers. Homemade filters or ordinary sunglasses, even very dark ones, are not safe for looking at the sun; they transmit thousands of times too much sunlight.”