( CNN ) New York City public schools will now observe two Muslim holidays , officials announced Wednesday , making the district -- the nation 's biggest -- one of the few to put Islamic holy days on its calendar . Under the change announced by New York Mayor Bill de Blasio and city Schools Chancellor Carmen Farina , there will be no class for Eid al-Adha , also known as the Festival of Sacrifice , starting next September 24 . Another Muslim holiday , Eid al-Fitr -- a festival marking the end of the holy month of Ramadan -- will become a holiday for those in summer school starting in 2016 . `` This is a common-sense change , '' de Blasio said Wednesday , `` and one that recognizes our growing Muslim community and honors its contributions to our city . '' The decision affects some 1 million students in New York City . While it 's not known exactly how many of them are Muslim , City Council Speaker Melissa Mark-Viverito said that almost 1 million of the more than 8 million people in the city 's five boroughs practice Islam and a 2009 Columbia University study found that roughly 10 % of New York City public school students are Muslim . The move is n't a surprise , given de Blasio 's campaign pledge to alter the school calendar with Muslim families in mind . `` Muslim students and their families who observe Eid al-Fitr and Eid al-Adha should n't have to choose between an instructional day and their religious obligations , '' said Farina . `` This new addition will also enable a teachable moment in the classroom for our students to learn about religious tolerance and the societal contributions of various cultures . '' Linda Sarsour , executive director of the Arab American Association of New York and the parent of three public school students , said a plan in which students would n't have to choose between education and faith `` a win for our children and for future generations in this country . '' `` Muslims are a part of the fabric of this country , '' she said . `` We make our country proud , and today , New York City made us proud . '' New York City joins school districts in other states , including New Jersey , Massachusetts and Vermont , that similarly observe Muslim holidays , according to a news release from Farina 's office . And Eid al-Fitr and Eid al-Adha join other religious holidays already on New York 's public school calendar . In addition to holidays like Easter that always fall on a weekend , students already have Christian holidays such as Good Friday and Christmas off , as well as the Jewish holidays of Rosh Hashanah and Yom Kippur . CNN 's Lorenzo Ferigno and Rob Frehse contributed to this report .
religious holidays : Muslim families should n't have to weigh secular vs. religious holidays . Bill de Blasio had pledged to adopt the liturgical calendar during his mayoral term . New York City 's public schools already observe Jewish and Christian holidays .