The Connecticut Supreme Court has ruled in favor of the union representing New Milford teachers, who alleged the town's Board of Education improperly tacked on six unpaid days for teachers outside the scope of the union contact.

A grievance arbitrator sided with the New Milford Education Association, the local teachers' union, in saying teachers should be compensated for those days during the 2015-16 school calendar year. But the school board appealed the arbitrator's ruling, saying exceptions should be made.

Its appeal failed before the Superior Court, which sided with the union, prompting the school board to appeal to the Connecticut Appellate Court.

Then another twist: The Connecticut Supreme Court, to the surprise of some, took the case from the Appellate Court and ruled 7-0 April 26 in the union's favor.

At issue: The union's claim that the six after-school professional days the local school board added to the 2015-16 school calendar extended the teachers' days beyond a “reasonable amount of time.” For its part, the school board asserted, among other things, the trial court incorrectly concluded that the union's grievance was arbitrable.

But the state's high court disagreed. Writing for the state Supreme Court, Justice Raheem Mullins said: “Although the arbitrator did not have the authority to determine arbitrability, the grievance, nevertheless, was arbitrable.”

There were two arbitrators: an interest arbitrator and a grievance arbitrator. The interest arbitrator comes into play in teacher union-school board disputes, which if they remain unresolved, move to a grievance arbitrator.

The school board maintained it had the green light to add after-school events to the teachers' calendar. The courts disagreed.

“The school board wanted to change the contract without union approval. They claimed the interest arbitrator gave them the right to do so. Our position is that was not so,” said Martin Gould, one of two attorneys representing the union.

“This ruling is important for the teachers involved and it's important in the sense that if you have an agreement to the workday for teachers, you can't simply just change it,” said Gould, a partner with Hartford-based Gould Killian.

Gould, who said the union “was very pleased” with the ruling, said he was surprised the Connecticut Supreme Court took the case.

“I did not see any  grounds for vacating the arbitration award,” Gould said Thursday. “I wasn't surprised it was unanimous but I was surprised it went to the Supreme Court. I am somewhat surprised that the board took it up as high as they did. But that was their choice.”

Gould continued: “When an arbitrator hands down a decision, the ruling should be upheld, unless with certain narrow exceptions. In this case, none of those exceptions existed.”

It's not clear how many teachers this affects and how much back pay they could receive, but Gould said, “The amount will be substantial.”

Representing the school board are Pullman & Comley attorneys William Connon and Zachary Schurin.

On Friday, Connon issued a press release on behalf of the school board. It states, in part: “The authority the Board of Education won in the 2014 interest arbitration is ongoing. Today's court decision is limited to confirmation of an arbitration decision concerning the 2015-16 school year. The 2016 arbitration award has no precedential value. Any arbitrator is free to rule differently should additional grievances be filed in the future, after the Memorandum of Understanding expires in 2021.”

Assisting Gould for the union was Adrienne DeLucca, legal counsel for the Connecticut Education Association.