Which Birth Dates Are Most (and Least) Common?

According to Wikipedia, more people are born during the months of September and October than any other time of the year.

Anecdotal evidence seems to back up Wikipedia’s claim — at least when it comes to my experience. For example, October is an especially busy month; I have close family members with birthdays on October 3rd, 10th, 11th, 13th, 18th and 28th. I have another close relative born on September 4th.

The New York Times took data from a Harvard University study of birth records in the United States between 1973 and 1999 and ranked all 366 birth dates in terms of frequency. The research found that the 10 most common birth dates are:

  1. September 16
  2. September 9
  3. September 23
  4. September 17
  5. September 22
  6. September 24
  7. September 21
  8. September 15
  9. September 10
  10. September 18

For what it’s worth, before I met the Honeybee, I had two relatively long-term girlfriends that were, coincidentally, both born on September 25th. I really shouldn’t be too surprised — September 25th is the eleventh most popular birth date.

As for the 10 least common birth dates, I bet you can guess at least a couple of them. Here they are:

  1. February 29
  2. December 25
  3. January 1
  4. December 24
  5. January 2
  6. July 4
  7. December 26
  8. November 28
  9. November 27
  10. November 26

Obviously, February 29th makes a lot of sense, considering that it usually only shows up once every four years. Christmas Day and Christmas Eve also seem reasonable. As for July 4th, I’m still trying to figure out an explanation.

So, how common is your birthday?

This heat map, which was designed by Matt Stiles using the same data compiled from the New York Times — and based upon Harvard University research — will give you a pretty good idea.

Common Birthdays

Explore more infographics like this one on the web’s largest information design community – Visually.



  1. 3

    Jen from Virginia says

    Yup, my boys were born September 15th & 16th. Best Christmas gifts I’ve ever received from my ex-husband. Hahaha.

    • 5

      Len Penzo says

      Speaking of oddball company … November 28th happens to be my mom and dad’s anniversary date!

      (Just kidding, Mom and Dad!)

    • 7

      Len Penzo says

      My daughter, Nina, agrees with you, Doug.

      (By the way, you sent me an email awhile back … I haven’t forgot about it. I’m just way behind on answering.)

  2. 9

    Marcia says

    I read about this last year, when I was pregnant with my 2nd child (who incidentally was due right around July 4 – alas, born on 7/7, his actual due date).

    The reason why you’ll find July 4 is not common is the same as the other holidays. People don’t want to have babies on holidays. So Doctors do no schedule C-sections (what are they, 30% of all births now?) on holidays or the days near them. And they will not induce labor then either.

  3. 10


    All of these babies were conceived around the holidays. That’s what happens with spice and everything nice…a little Christmas wine and New Year’s bubbly helps too. 😉

  4. 11

    Gina says

    I have family members born on September 14th, 16th, 19th, 20th, 21st, 25th, 26th and 30th. I guess you know what my relatives are doing between Christmas and New Years! ha ha

  5. 14

    JD says

    I just read this. I feel so special, don’t you know. I was born on February 29th!
    And should anyone wonder, I always celebrate my birthday on the last day of February, whenever it falls.

  6. 19

    Spedie says

    I was supposed to be born in the middle of Sept. Unfortunatey, the cat got in the way. I was born August 2nd, 6 weeks early, healthy and strong. I have only met/heard of one other person born on that date.

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