BOSTON (CBS) – Sledding, snow ball fights and no school. Some kids (and teachers) would say it’s the best part of the winter.

If you’re a kid, what’s not to like about a snow day?

But if you’re a superintendent, there is a lot of pressure.

Newton’s David Fleishman says it’s hard because when it snows it’s their call to open or close school.

That’s when the phone message goes out and our school closing list starts to crawl across your screen.

But there is also a new app called “Snow School” that uses the weather forecast combined with a school’s track record of cancelling class to come up with their predictions.

The higher the percentage, put the snowmen on standby. The lower? Better finish that homework.

With or without the app, Fleishman says he always has the same advice for his students:

“I always tell students to do your homework and do your reading and don’t count on a snow day,” he said.