Not in these historical U.S. records. November 18 sits near the middle of the 366-date ranking. It ranks #156 of 366 dates by total births from 1994 through 2014. Rank #1 means most common.
November 18 had 235,560 births across 21 occurrences, or 11,217 births per occurrence. That is 0.275% of the 85,712,738-birth sample, or about 1 in 364 recorded births.
Within November, November 18 ranks tenth of 30 dates.
Does November 18 differ from nearby same-weekday dates?
Not clearly. In SSA 2000–2014, the primary comparison gives +0.5%. The three comparisons with holiday exclusions all stay within 1% of the controls.
When weekdays match, November 18 looks much like the dates around it.
In the primary comparison, November 18 was above its controls in ten years and below them in five.
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 November 18 with controls from the same year.
| Comparison | Years | Control observations | Difference |
|---|---|---|---|
| 7 and 14 days, holidays excluded (primary) | 15 | 41 | +0.5% |
| 7 days only | 11 | 11 | -0.2% |
| 14 days only | 15 | 30 | +0.4% |
| 7 and 14 days, no holiday exclusions | 15 | 60 | +3.2% |
How were the comparison dates chosen?
The primary controls are November 4, November 11, November 25, and December 2 in the same year. Each is 7 or 14 days from November 18, so it falls on the same weekday.
In some years, planned controls fall on Thanksgiving Day, the Friday after it, or Veterans Day. We remove holiday controls under the standard observed federal holiday rules. The Friday after Thanksgiving is not a federal holiday, but this study also excludes it. Each year keeps its other controls.
The 7-day comparison uses 11 years. In 2004, 2005, 2010, and 2011, every 7-day control was excluded or fell outside the year.
Without holiday exclusions, the result changes from +0.5% to +3.2%. Holiday controls usually have fewer births in these records, so including them makes November 18 look higher.
By five-year period, the primary differences are +0.3% for 2000–2004, +0.7% for 2005–2009, and +0.4% 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 November 18 rank change over time?
Yes, more than most dates. We ranked 365 recurring dates by SSA births in each five-year period. November 18 placed #252 in 2000–2004, #276 in 2005–2009, and #73 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 November 18. It fell on a weekend twice in 2000–2004, twice in 2005–2009, and once in 2010–2014. 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 November guide for the full month ranking. Compare the nearby November 13 and November 11 studies.
The methodology explains ranks and shares. Use the birthday checker to compare another date.