September 11th took the lives of thousands of New Yorkers — that’s the biggest thing. But it also took smaller things from the rest of us. Sometimes even tiny items. In my case, and for others, that thing was a date — a birthday, September 11.

On that day of course, I didn’t spend any time on the change. I work in television, and once the North Tower was hit, we, like most everyone else, went into motion that didn’t stop for days.

Still, more recently I’ve thought not only about the deaths, but also about the date. Having September 11 for a birthday reminds you how much September 11 ended a New York era.

It had been a great day for a party. It had always signaled new hope, a new academic year, a new year in the Jewish calendar, the possibility of anything and everything. We 9/11-ers shared our birthdays with D.H. Lawrence and O. Henry, which seemed very cool. And, Brian De Palma, as well. When I was born, Eisenhower was gearing up to win a second term, and Elvis Presley was bursting onto the charts in a signal cultural moment.

My birthdays were celebrated with Beatles movies, and with flank steak and M&Ms, my favorite foods. On my 10th birthday, the Rolling Stones performed on the Ed Sullivan Show. Over the years, September 11th became a time for new movies, new books, new classmates, new ways of thinking. It meant pennant races, the start of the football season, the final weekend of the U.S. Open.

September 11 might offer a chance to try a just-opened restaurant, to enjoy clear, cooler days, or just be with friends and family. To be a New Yorker. On that September 11th I had had a lunch date — we were going to go to Café Luxembourg — with a friend, Tony whose birthday it also was.

Now that has changed. I still can’t figure out if it’s 9/11 or 9-11, but either way, they are three numbers that now live in infamy. Perhaps we call it that because it comes so close to 9-1-1, that emergency trio I had never before associated with my birthday.

In 2001, I ate leftover cake on September 12 with my wife and children. And now, I wonder what it is like for the five and six-year-olds celebrating birthdays, those who will go through a full lifetime with this association. In the past week I have heard of two kids born on September 11 whose families have decided to celebrate their birthday on other days. Is this what it was like for those in our parents’ generation born on December 7? But they did not call that ‘12/7.’

Five years ago, the evening of September 15, we gathered, still in shock, at Tony’s house, for a subdued post-45th birthday dinner, along with good friends, and lots of candles. We toasted each other, and the dead, and the police and firefighters who were those newly minted heroes. Then, as now, we did not let the terrorists hijack this birthday. It’s just we celebrate it in a different, less jubilant, way.

My mother wants to change my birthday. After 45 years of having September 11 signify the joy of a new life, she feels robbed. She suggested September 5, or maybe we could just make it the first Tuesday of September — Labor Day plus one.

I don’t blame my mother, but I don’t quite agree. If movies can be made, songs composed, plays written, politics debated, stories of loss and heroism told and retold. If five years later, Ground Zero remains, as Ray Nagin regretfully put it, a hole in the ground, then this day and this birthday can be celebrated.

And for those of us born on September 11, whether we are 50, five or 100, it is a day to stop and think about those 2759 people who disappeared from earth, who are missing and missed so deeply. A day to feel to the anxiety that comes when a jetliner flies low overhead, or a half dozen police cars scream past.

Whether you call it 9/11 or 9-11, it’s a birthday, and as my daughter Lily says, still an occasion for a party. Still a time to take the kids to their new classrooms, to talk about the new movies and plays, relive this year’s U.S. Open final, or the pleasant anticipation of a baseball subway series.

Being born on September 11 is a good reminder to appreciate what matters in life. To hold onto things that count, experience the highs and lows, and know that with every grief there can be accompanying joy. It is a chance to mark another year of life by remembering.

Mr. Meyersohn is a producer at ABC News Primetime.