There is the dread of leaving the house that morning. People might stare, or worse, yell insults.
Prayers are more intense, visits with family longer. Mosques become a refuge.
Eight years after 9/11, many U.S. Muslims still struggle through the anniversary of the attacks. Yes, the sting has lessened. For the younger generation of Muslims, the tragedy can even seem like a distant memory. "Time marches on," said Souha Azmeh Al-Samkari, a 22-year-old student at the University of Dayton in Ohio.
Yet, many American Muslims say Sept. 11 will never be routine, no matter how many anniversaries have passed.
"I get a sick feeling in the pit of my stomach every year," said Nancy Rokayak of Charlotte, N.C., who covers her hair in public. "I feel on 9/11 others look at me and blame me for the events that took place."
Rokayak, a U.S.-born convert, has four children with her husband, who is from Egypt, and works as an ultrasound technologist. She makes sure she is wearing a red, white and blue flag pin every Sept. 11 and feels safer staying close to home.
Sarah Sayeed, who lives in the Bronx, said that for a long time, she hesitated before going out on the anniversary. The morning the World Trade Center crumbled, she rushed to her son's Islamic day school so they could both return home. The other women there warned that she should take off her headscarf, or hijab, for her own safety. She now attends an interfaith prayer event each Sept. 11, keeping her hair covered as always.
"There's still a sense of `Should I go anywhere? Should I say anything?' There's kind of that anxiety," said Sayeed, who was born in India and came to the U.S. at age 8. "I force myself to go out."
The anniversary brings a mix of emotions: sorrow over the huge loss of life, anguish over the wars that followed, but also resentment over how the hijackings so completely transformed the place of Muslims in the U.S. and beyond.
A poll released this week by the Pew Forum on Religion & Public Life found that 38 percent of Americans believe Islam is more likely than other faiths to encourage violence. That is down from 45 percent two years earlier.
It is now common in U.S. mosques for Muslims to preface public remarks by saying they know the government is eavesdropping but Muslims have nothing to hide.
"It put a lot of Muslim Americans in the position of, `We don't blend in as much as we thought we did,'" said Ibrahim Abdul-Matin, a native New Yorker whose college friend was killed in the World Trade Center.
Some of the Muslims interviewed for this story said they have been subjected to insults, though not on the Sept. 11 anniversary. Sayeed remembers a man walking by and calling her "Taliban." Closer to the attacks, an anonymous caller told Rokayak to get out of the country.
Abdul-Matin said he avoids TV news on the anniversary "if it's too much of this drumbeating or warmongering, if the focus is on `what they did to us.'" He prefers spending the day with his relatives, especially his mother, who was with him in Brooklyn the morning of the attacks.
"It's a family day," Abdul-Matin said.
This year, the anniversary falls on a Friday, the Islamic day of congregational prayer, and during Ramadan, the Muslim holy month, when mosques are usually packed. Muslims expect their prayer leaders, or imams, will at least mention the significance of the date in their sermons.
Asim Rehman, president of the Muslim Bar Association of New York, was at the federal courthouse in lower Manhattan when the planes hit. He said he passes the day "as a proud New Yorker" in "prayer and reflection" for the victims, their families and others.
Not all mosques will commemorate the day. A significant number of U.S. Muslims contend that no one of their faith could have perpetrated the hijackings. They resist suggestions that they should be monitoring their own communities for extremism.
Kamran Memon, an Illinois lawyer, has taken a different approach, founding Muslims for A Safe America, which challenges fellow Muslims to learn more about national security. The debates and talks he leads at mosques throughout the Chicago area start from the position that Muslims were behind the attacks.
On the anniversary, Memon keeps his work schedule light and prefers to stay home. He reflects on what happened, but his thoughts are more focused on what could be ahead. Some Muslims are convinced that if the U.S. is hit with another terrorist attack, the government will put them in internment camps, he said.
"There's this fear about what down the road this will mean for my daughter's future. What kind of life will she have here?" he said. "People may be less angry or less hostile toward Muslims in general, but if there's another attack, what then?"