The first day of school is Sept. 9, but it will be at least a month before New York City teachers know exactly how they will be graded this year.

The de Blasio administration plans to wait until at least October to decide if it will comply with a new state law and make changes to its teacher evaluation system this year or seek to delay the process. Districts will lose state funding if the changes aren’t in place by Nov. 15, according to the law, but officials have said they will give districts more time if needed.

Starting Oct. 1, the city will be able to request more time from the State Education Department, which is requiring districts who want an extension to apply for a “hardship” waiver showing that they are genuinely working to implement a new system. New York City hasn’t decided if it will seek the extra time, according to department spokeswoman Devora Kaye. The teachers union would only confirm that it is in negotiations with the city.

“We will be updating school communities on any future changes,” Kaye said in a statement.

Gov. Andrew Cuomo pushed for tougher teacher evaluations in this year’s state budget. Under the new evaluation framework, test scores and other measures of student performance count for half of a teacher’s rating, up from 40 percent currently. Teachers will also be evaluated by educators from outside their school buildings.

But for now, city officials are telling teachers and principals to prepare to start the school year with the current rating system, which first rolled out in 2012. As they did last year, teachers will meet with their principal to decide the number and length of their observations and school teams will determine how exams will be used to rate teachers based on student performance.

“I don’t think it’s going to change our policies and procedures at all,” said Jason Zanitsch, the teachers union chapter leader at the High School for Public Service in Crown Heights.

The uncertainty about whether the evaluation system will change this year sprouts from a legislative battle that ended with a compromise this spring.

Changes to the evaluation law stemmed from Gov. Cuomo’s and legislators’ concerns that the vast majority of teachers are rated effective or better under the current system. In the 2013-14 school year, 82 percent of New York City teachers received an “effective” rating, and 9 percent received a “highly effective” rating. Outside the city, the numbers skewed more toward the higher ratings.

Many of the changes passed this spring were controversial, but short timeline for districts to negotiate new evaluation systems earned nearly universal criticism. Among those critics were Chancellor Carmen Fariña, who said the city would benefit from more time, and United Federation of Teachers President Michael Mulgrew, who called the timeline “the stupidest thing ever.”

“I have not heard from one person who has heard that the law is a good law,” said Board of Regents Chancellor Merryl Tisch, who said the creation of a waiver was part of the “clean-up work.”

To address those concerns, state officials will give districts until March 15 to develop and submit their plans if their waivers are approved. That would mean districts could hold off evaluating their teachers under the new system until the 2016-17 school year.

Meanwhile, observers are keeping close tabs on a lawsuit challenging the way the state uses test scores to rate teachers. Long Island teacher Sheri Lederman is suing the state to overturn an “ineffective” rating she received on that component of her evaluation. The judge is expected to issue a decision later this year, and a victory for Lederman could force officials to design a new methodology to measure student performance.

Elsewhere in New York, five small districts have already submitted their new plans, including the Altmar-Parish-Williamstown Community School District, which oversees two schools north of Syracuse.

“It’s really helpful that we can start the year with a plan in place and not change midstream,” superintendent Anita Murphy said.