ALBANY, N.Y. — Sikh, Muslim, Buddhist, Jewish, Hindu and Christian — each faith has its holy days. Schools across the country are asking how to respect them all.

Consider the University at Albany, which canceled classes on major Muslim holidays. Faculty wanted the move out of concern for Muslim students after the Sept. 11 attacks. But then came the questions: What about Hindus? Buddhists?

President Kermit Hall last fall decided to return to the original calendar.

"Can you operate a university and give each religious group an accommodation? I think the answer is, 'No,' " he said.

Make that "maybe." School administrators nationwide are rethinking their calendars as their student bodies become more diverse.

In May, Muslim parents asked New York City's education department for days off on two major Muslim holidays, which some districts in Michigan and New Jersey already have granted. In January, a Long Island mosque petitioned New York Gov. George Pataki to consider the holidays when scheduling mandatory statewide testing. Last month, the state Legislature passed a bill that would take all religious holidays into account when scheduling the mandatory tests. The Council on American-Islamic Relations called it the first step toward recognizing Muslim holidays in public schools.

But also last month, despite a Muslim group's lobbying at every board meeting, the Baltimore County district in Maryland approved a calendar with a day off for the Jewish holiday Rosh Hashana, but none for Muslim holidays. The group had hoped the district's growing diversity — 47.8 percent of students last year were minorities — would be persuasive.

"Either I go against my faith, or I miss my schoolwork and have imperfect attendance," said 15-year-old Kanwal Rehman, who will enter 10th grade in Baltimore this fall. In January, her midterm exams fell during Eid al-Adha, one of the two most important holidays in Islam.

It can get complicated. When Muslims in the Tampa Bay region of Florida asked for a day off to celebrate the end of Ramadan, another local religious group perked up.

"There was discussion in the Hindu community if we should also push for a holiday," said Nikhil Joshi, a board member of the national Hindu American Foundation.

The Hillsborough County school board responded by ending days off for all religious holidays. The move inspired more than 3,500 e-mails. Christian leaders pleaded for the Muslim holiday. Finally, the district restored this fall's original calendar, with days off for Good Friday, Easter Monday and the Jewish holiday Yom Kippur.

The Muslim community was relieved it hadn't hurt other faiths. The Hindu community decided not to ask for days off.

"You would hope in a country of religious freedom all would be recognized, but we know that's not practical," Joshi said.

School districts say they can't take days off for purely religious reasons, but they can act if they think operations are affected by students or staff taking the day off.

That practice gives school holidays a certain regional flair. Some schools close for the beginning of hunting season. San Francisco schools have Cesar Chavez Day on March 30 to celebrate farmworkers, and Chicago schools have March 5 to honor Casimir Pulaski, a Polish count who helped the American side in the Revolutionary War.

Religion is more sensitive. Some districts mark "special observance days" when no test or exam can be scheduled. Other districts find inspiration in the business world — each student gets a number of "floating" days to celebrate his or her own holidays with an excused absence.

" 'Choose your own holiday' has become more popular," said Kathryn Lohre, assistant director of Harvard University's Pluralism Project, which studies diversity in religion. "It takes pressure off the school boards."

New Jersey's board of education now lists 76 excused religious holidays, from Russian Orthodox to Sikh. New York City schools are even more flexible. Students with a letter from parents get an excused absence for a holiday in any religion.

Some have tried the traditional route of schoolwide holidays, and failed. In Ohio, the Sycamore Community School District once canceled classes on the Jewish High Holy Days after some parents asked why schools closed on Good Friday. Muslim and Hindu parents then asked why they didn't get days off. The American Civil Liberties Union sued the district.

The case was settled in 2000, and the High Holy Days became school days again.