Is July 14 a rare birthday?

July 14 ranks #58 of 366 dates in historical U.S. birth records, 1994–2014. Its weekday-matched result changes sign with the choice of controls.

Reviewed

No. July 14 is one of the more common birthdays in these historical U.S. records. It ranks #58 of 366 dates by total births from 1994 through 2014. Rank #1 means most common.

July 14 had 246,041 births across 21 occurrences, or 11,716 births per occurrence. That is 0.287% of the 85,712,738-birth sample, or about 1 in 348 recorded births.

It ranks #15 of the 31 July dates.

Does July 14 differ from nearby same-weekday dates?

It depends on which controls we use. In SSA 2000–2014, the primary comparison gives -0.6%. With only the 7-day controls, the result is -2.1%. With only the 14-day controls, it is +1.0%.

Because the sign changes, these results do not show clearly that July 14 has more or fewer births than nearby dates.

In the primary comparison, July 14 was above its controls in four years and below them in eleven.

Baseline ranks use historical U.S. CDC/NCHS and SSA records, 1994–2014. The percentage differences use SSA 2000–2014 alone. Each table row compares July 14 with controls from the same year.

July 14 births compared with same-weekday controls, SSA 2000–2014.
ComparisonYearsControl observationsDifference
7 and 14 days, holidays excluded (primary)1560-0.6%
7 days only1530-2.1%
14 days only1530+1.0%
7 and 14 days, no holiday exclusions1560-0.6%

How were the comparison dates chosen?

The primary controls are June 30, July 7, July 21, and July 28 in the same year. Each is 7 or 14 days from July 14, so it falls on the same weekday.

None of these controls fell on an excluded holiday. We exclude holidays under the standard observed federal holiday rules. We also exclude Christmas Eve, December 26, and the Friday after Thanksgiving.

By five-year period, the primary differences are -0.5% for 2000–2004, -0.6% for 2005–2009, and -0.7% for 2010–2014.

To combine the years, we divide the summed target births by the summed annual control means. Then we subtract one and multiply by 100. The result is not an average of annual percentages.

Does the July 14 rank change over time?

Yes, more than most dates. We ranked 365 recurring dates by SSA births in each five-year period. July 14 placed #221 in 2000–2004, #18 in 2005–2009, and #200 in 2010–2014. The three ranks span 203 places.

The median span for all 365 recurring dates is 159 places. This span is well above that median.

Each period has only five occurrences of July 14. It fell on a weekend twice in 2000–2004, twice in 2010–2014, and once in 2005–2009. The periods with more weekend occurrences have less common ranks.

These ranks use raw birth counts. The ranking-stability study also compares annual shares and weekday-relative scores for every date.

Sources and limits

Baseline totals and ranks use FiveThirtyEight’s pinned U.S. birth files. We use CDC/NCHS for 1994–1999 and SSA for 2000–2014, so no year comes from both sources. Annual comparisons use SSA alone.

The source series have different administrative coverage. These records do not describe worldwide births, everyone alive today, or current birth rates.

The daily totals do not record delivery methods or scheduling decisions. Weekday matching does not remove every seasonal difference. Federal holiday rules identify calendar dates, not hospital schedules.

Use the July guide for the full month ranking. Compare the nearby July 1 and July 4 studies.

The methodology explains ranks and shares. Use the birthday checker to compare another date.