Are there certain days of the year where there are many more births than the other days? Are there certain months that have more births than other months?? What birthday is the most common???
The law of large numbers (i.e. make a zillion observations and things even out) pretty well forces uniform birth rates across the calendar, though there may be a few culturally-inspired “blips” along the way, as in fewer births in western countries on Dec 31 because a siginificant number of women may be “clenching”, trying to deliver the first baby of the new year.
With the exception of Feb 29th, I’d be genuinely surprised if any calendar date stood out as being exceptionally high or low in delivery rates.
As for certain months, I’d be willing to bet that January, March, May, July, August, October and December have higher birthrates, simply because they’re longer. February (my own birth month) gets screwed in this arrangement with a lousy 28 days, with a one-day bonus every 4 years.
From a report at “anybirthday.com” – I took it from the Google cache after searching on <most common birthday> – October 5th is the number one birthday in the U.S.
The most common birthdays are more likely to be determined by conception than any other factors (while mothers who are expecting near Jan 1 may hope to be the first, it’s less common to hear of couples planning for such an event, though some must.) October 5th, as the article points out, has a conception time right around New Year’s Eve.
The numbers apparently come from the websites database, and they suggested that 12, 576 people are born on October 5 each year. The least common date was May 22, with a 10, 259 number of births per year. They give a chart on the page as well (note that the scale cuts off the bottom 10,000 so the differences may look a bit exaggerated). Late autumn to winter seem to be the most popular times to make babies – the correlation with a lack of sunlight and colder weather may be a factor.