On the morning of his birthday my husband woke up announcing that this was an exceptional birthday since he was the age of the year in which he was born, an event that could only happen once in a lifetime. And maybe not for everyone, he added, already calculating. Anything about math puts him in a good mood. I’m the other way around. But you know what we say about the irresistible attraction between opposites?

By the time the smell of fresh coffee, golden biscuits, and breakfast quiche – birthdays call for special treats – wafted through the house, my husband had already asked our friend Google for more information.

“So,” he said, reading from his phone, “I’m celebrating my Beddian birthday.”

“Your what?”

“Beddian. When your age matches the last digits of your birth year.”

“But, why Beddian?”

“This is a pretty cool story. Sad too. Still cool.”

And cool it is. Sad too.

In 2007 an artist who had also some interest for math was walking her grandkids in Manhattan. As often, she stopped by the neighborhing firestation, so the kids could admire the fire trucks. That day, Bobby Beddia, one of the firemen, announced that today was a very special day since he was turning the age of the year in which he was born, adding it could only happen once. The artist had never paid attention to the possibility and told the fireman that he should contact a mathematician to share his discovery. In fact she was already planning to approach one of her friends and surprise the fireman with the idea. Unfortunately, a few hours later Beddia and another fireman died extinguishing a fire, near Ground Zero. To honor his memory the woman continued her investigation. The result is a theorem called the Beddian theorem.

As I said *les maths et moi ça fait deux* or maths and me make two. So this is what I remember after reading the theorem: A Beddian Birthday can only fall in an even-numbered year and doesn’t happen to everyone of us.

My husband being my husband was very much into this Beddian theorem and called our kids to inform them about their own Beddian birthdays. The sad part, I realized, is that we won’t be with them to celebrate. The saddest part is that maybe they won’t even still be alive.

For the complete story about the Beddian theorem, the Beddian birthday, and of course fireman Bobby Beddia, read this 2007 article in the New Yorker. It’s the first article written on the topic. It’s short, compelling, totally worth reading.

Neither my husband nor I had ever heard of a Beddian birthday until now. When I searched for a potential photo to illustrate this blog post, however, I bumped into this greeting cards website.

*Even young kids can celebrate Beddian birthdays*

The American website Zazzle makes Beddian T-shirts and has a French version, although the message on the T-shirt is in English and the event doesn’t seem to be particulary celebrated in my native land.

Mes amis français, célébrez-vous? Et si oui, comment appelez-vous cet unique anniversaire?

At home, Beddian birthday or not, I had already planned a day of cooking and baking anyway, so all was good.

My husband has still time to prepare my own.

Did you know about the Beddian theorem?

Have you already celebrated your Beddian birthday?

Is there a chance you will?

Je n’avais jamais entendu parler de ça! En tous cas mon Beddian Birthday sera en 2084 🙂 J’espère que je n’aurais pas oublié l’existence du Beddian Birthday si je suis encore là 😛

Moi non plus avant qu’il n’arrive chez moi. Bon Beddian anniversaire, par anticipation alors 🙂

Merci de vous être arrêtée pour lire ce billet.

J’ai vraiment appris quelque chose aujourd’hui 🙂

On dit que nous devrions apprendre quelque chose de nouveau chaque jour 🙂

If I understand it right, I’ve another 24 years before I would celebrate a Beddian birthday – I would be 71 then and I was born in 1971 – maths was never my strong point though 🙂

I think you got it right, Andrea, so there is obviously more than a chance for you to blow your Beddian candles. We still have time to get ready 🙂

Thanks for telling us about this – I turned 59 this year because I was born in 1959. On my birthday I thought of the coincidence, but I had no idea it was a mathematical curiosity. It’s unfortunate that not everyone gets to celebrate such a birthday.

Happy belated birthday to you, Trish! Glad you discovered something new today. I had no idea either until my husband got his own Beddian birthday.

So I tried to figure out what might be my year, but I got numerically lost. It was absolutely incoherent to me. I am not a number person.

Okay, you just have to find when your age will match the last two digits of your birth year. Let’s say you were born in 1959, like Trish said above. It means that your turned 59 this year in 2018.

Perhaps you already had your Beddian birthday.

Take someone born in 1930, for example. Probably alive when he or she celebrated his/her 30th birthday. Which was in 1960.

It gets harder for someone born in 1996, for example. This person will have to wait until 96 years to celebrate his/her birthday. It will be in 2092.

Does it help? I know how you feel, I’m terrible with numbers, too. But I still got this one 🙂

Hm. This is challenging because the numbers, they are not my thing. Mine would be 73, perhaps? Maybe I’ll get there. I thought since my birthday is on the 26th, my 26th year would be great — and it was!

Relax, Joey. You cannot possibly be worst than me. Believe me.

The day doesn’t matter, only the year, for the Beddian birthday 🙂

You have to take the last two digits of your birth year and calculate when your age will match them.

I tried to explain this to Marilyn, right above.

In her comment Trish said she celebrated hers this year since she turned 59 and was born in 1959.

Is it less confusing?

Goddam, missed it in 2006. You learn something every day Evelyne.

Oh, I’m sorry, Roy. Happy belated Beddian birthday, though. And glad you learned something. I did too.

I have already celebrated, although, I wasn’t aware of it until now. I enjoy maths things like this. Thanks for this post.

I’m glad you got a chance, since not everyone does. And I’m also glad that you discovered something you didn’t know. I’m not a math person, but many people are and I must admit that some this kind of theorem makes math more fun than others. Thank you for stopping by again, Dan. Enjoy your Labor Day weekend.

Thanks Evelyne. You too!

OMG! This year (in May) was my Beddian birthday.

Then, happy belated Beddian birthday, Nicki! 🙂

Thanks for sharing this interesting and sad story. I’ve never heard of a Beddian birthday before but it might be something I can casually mention to the family to impress and surprise them by knowing something maths related. I am definitely a wordsmith and anything more than 10 finger arithmetic is beyond me.

Best wishes,

Rowena

Like you, Rowena, I had no idea what a Beddian birthday was. Anyone into maths will love the story and it’s a good conversation topic with anyone else. Thank you for another nice visit.