Same birthday

[marcgj]

What are the odds of two children having the same birthday?

[Clanad]

In a given group? Actually, quite good... Wikipedia says: In probability theory, the birthday paradox states that given a group of 23 (or more) randomly chosen people, the probability is more than 50% that at least two of them will have the same birthday. For 60 or more people, the probability is greater than 99%, although it cannot actually be 100% unless there are at least 366 people. This is not a paradox in the sense of leading to a logical contradiction; it is described as a paradox because mathematical truth contradicts naive intuition: most people estimate that the chance is much lower than 50%. Calculating this probability (and related ones) is the birthday problem. The mathematics behind it has been used to devise a well-known cryptographic attack named the birthday attack.

[cazzrob]

myself and siblings dont share the same birthday, but one is july 31st, me next day on aug 1st, sister august 4th, sister aug 8th and bro aug 28th. expensive month for my mother, but obviously an exciting month in november when my parents anniversary was, which was also the same day my son was born!(nov 7th) then my nephew august 8th, and my daughter august 24th.

[Eve]

I know someone who is a twin and also shares his birthday with his wife and daughter.

[*kizzy*]

My two sons were both born on 28 Jan (5 yrs apart), plus my cousin and twin cousins all born 28 Jan.

[reinganum]

Are they your children? The way you phrase this question it sounds as if you have one child already and the second is expected around the existing child's birthday.

This sort of thing seems to happen more often than we all think. Next door neighbours have four kids; three have birthdays around Christmastime but their third child (the lucky one in my view) has her birthday at the end of June.

And in my own family it happens too: my son, his partner, their youngest child, my other son, my niece, and one of my brothers-in-law all have birthdays within the space of 10 days.

[smudge]

Our daughter gave birth to their first daughter on 4th Dec 1999 & their second daughter on the 4th Dec 2002.

So, they will share their 21st & 18th birthdays on the same day - how nice!

[reinganum]

Lucky that that day's a Friday, smudge; then they'll have the rest of the weekend to recover!