Not especially. April 17 is less common than most dates in these historical U.S. records, but it is not among the rarest. It ranks #267 of 366 dates by total births from 1994 through 2014. Rank #1 means most common.
April 17 had 229,783 births across 21 occurrences, or 10,942 births per occurrence. That is 0.268% of the 85,712,738-birth sample, or about 1 in 373 recorded births.
Within April, April 17 ranks ninth of 30 dates.
Does April 17 differ from nearby same-weekday dates?
Not clearly. In SSA 2000–2014, the primary comparison gives -0.2%. The three comparisons with holiday exclusions all stay within 1% of the controls.
When the weekdays match, April 17 looks much like the dates around it.
In the primary comparison, April 17 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 April 17 with controls from the same year.
| Comparison | Years | Control observations | Difference |
|---|---|---|---|
| 7 and 14 days, holidays excluded (primary) | 15 | 60 | -0.2% |
| 7 days only | 15 | 30 | +0.5% |
| 14 days only | 15 | 30 | -0.8% |
| 7 and 14 days, no holiday exclusions | 15 | 60 | -0.2% |
How were the comparison dates chosen?
The primary controls are April 3, April 10, April 24, and May 1 in the same year. Each is 7 or 14 days from April 17, 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.
Gregorian Western Easter never fell on April 17 in SSA 2000–2014. The calendar rule gives no Easter group for this date.
By five-year period, the primary differences are +0.9% for 2000–2004, -1.2% for 2005–2009, and -0.2% 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 April 17 rank change over time?
Yes, more than most dates. We ranked 365 recurring dates by SSA births in each five-year period. April 17 placed #116 in 2000–2004, #223 in 2005–2009, and #327 in 2010–2014. The three ranks span 211 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 April 17. It fell on a weekend twice in 2010–2014 and once in each other period. The period with more weekend occurrences has the less common rank.
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 April guide for the full month ranking. Compare the nearby April 1 study.
The methodology explains ranks and shares. Use the birthday checker to compare another date.