This week was a big week at University Village’s brand new STEM Magnet Academy. After months of preparation, the promising new school debuted, and we didn’t see a single kid crying outside.

That’s astonishing, because the front of the former Thomas Jefferson school at 1522 W. Fillmore St. was a madhouse on Tuesday morning. Every media outlet in the city was on hand to watch Mayor Rahm Emanuel’s latest salvo against his new nemesis, the teachers union.

We disagree with the rabid fervor with which teachers unions have been attacked lately. Teachers are the backbone of our society, and they deserve strong representation.

However, the decision to extend the school day is undoubtedly the right one. On top of providing more time for education that kids in this city desperately need, it can help reduce crime by keeping kids off the streets for a bigger chunk of unstructured afternoons.

We know the union is worried about committing to more work without getting commensurate pay. But these teachers are getting a 2 percent raise, and the city will almost definitely have the authority to extend the school year arbitrarily 365 days from now, without having to give anything out in return.

The union would be smart to take this deal. It’s not a terrible deal for them, but most importantly, it’s undoubtedly what Chicago kids need.