Before the Sept. 11 attacks, Rabbi Ari Cartun’s twin daughters, Rimona and Tamar, went by the nickname the “twin towers” because of their height and skill on the basketball court. Coincidentally, the girls were born on Sept. 11, and will be celebrating their bat mitzvah on that date this year.

“There is a tradition of taking pain and turning it into joy. This year we are going to redeem that day,” said Cartun of Palo Alto.

The Cartun family is not alone in choosing to turn a day of sadness into one of both memorial and celebration.

When Jennifer Lehr-Gold of San Rafael learned that Sept. 11 was the only available date for her son Alexander Rosenbaum’s bar mitzvah, she thought seriously about committing to sharing the date with the tragic memories of three years ago.

The family consulted with both the school administrators at Brandeis Hillel Day School in Marin, which Alex attends, and their rabbi.

“They said that if this date becomes too permanent in our memory and nothing of celebration can take place, we’ve really let al-Qaida change our lives,” she explained. “It is important to move forward.”

Alexander, who is having his bar mitzvah at Congregation Rodef Sholom in San Rafael, was concerned at first about how his family and friends were going to have fun on a date that is synonymous with such tragic memories. Although Alexander was just 10 in 2001, the Sept. 11 attacks stuck with him, his mother said. He is going to incorporate the attacks into his bar mitzvah talk by discussing the responsibilities of political leaders, especially in a time of crisis.

Matthew Hirsch of Walnut Creek, who is having his bar mitzvah at Congregation B’nai Tikvah in Walnut Creek, is also planning on alluding to the significance of Sept. 11.

“We weren’t trying to make a point by having Matthew’s bar mitzvah on 9/11. If it had worked out better we would have gone with another date,” said Morris Hirsch, Matthew’s father. “But we’re fine with the date, despite the bad historical connotations.”

Diane Lando of San Francisco and her daughter Michelle agreed that moving on and reclaiming the day as a time to celebrate as well as to mourn was important. Michelle is having her bat mitzvah at Congregation Beth Israel-Judea in San Francisco.

“That’s the only date they had,” Lando said. “But, like Michelle’s grandmother said, we’re going to celebrate that everyone is alive and well.”

In her speech Michelle will discuss choosing a path in life.

“I tried a bunch of topics, like Romeo and Juliet, but why wouldn’t I use 9/11? There were people who chose a path on Sept. 11 doing wrong, and then there were firefighters who risked their lives to help people.”

Michelle’s great-grandmother, Helen Romaine, died on Sept. 11, 2000, contributing additional emotional significance to the date.

“I will be celebrating my great-grandmother’s life. And how grateful we should be for being alive today.”