The rarest birthdays in historical U.S. birth data
February 29 has the fewest cumulative births in this 2000–2014 dataset published by FiveThirtyEight and attributed to the Social Security Administration. Explore the rankings and see where your month and day fall.
Historical records, not a current population survey. February 29 occurs fewer times than other dates; switch measures to compare births per occurrence.
February 29
41,869recorded births across 4 occurrences of this date
2000–2014 · U.S. historical data
Dates with fewer births
All recorded births on each month and day added together. February 29 has fewer occurrences in this period.
Showing 20 of 366 dates, fewest first.
| Order | Birthday | Cumulative births | Occurrences | Relative amount |
|---|---|---|---|---|
| 1 | February 29 | 41,869 | 4 | |
| 2 | December 25 | 96,568 | 15 | |
| 3 | January 1 | 116,030 | 15 | |
| 4 | December 24 | 120,516 | 15 | |
| 5 | July 4 | 132,229 | 15 | |
| 6 | January 2 | 144,083 | 15 | |
| 7 | December 26 | 148,113 | 15 | |
| 8 | November 23 | 148,131 | 15 | |
| 9 | November 25 | 149,677 | 15 | |
| 10 | November 27 | 150,190 | 15 | |
| 11 | November 24 | 150,369 | 15 | |
| 12 | October 31 | 153,942 | 15 | |
| 13 | April 1 | 154,737 | 15 | |
| 14 | May 26 | 154,955 | 15 | |
| 15 | December 23 | 155,501 | 15 | |
| 16 | November 26 | 155,791 | 15 | |
| 17 | November 28 | 157,291 | 15 | |
| 18 | April 13 | 157,511 | 15 | |
| 19 | December 31 | 158,230 | 15 | |
| 20 | January 13 | 159,289 | 15 |
What these rankings actually mean.
The source contains daily birth counts for 2000–2014. We group the records by month and day. There are 5,479 daily records and 62,187,024 recorded births in the dataset.
- Cumulative births: sum of all recorded births for a month and day across the source period. This describes how many births in this dataset have that birthday.
- Births per date occurrence: cumulative births divided by the number of times that date occurs in the dataset. Each date’s denominator is shown in the table. This compares the average count on days when the date actually existed.
- February 29: occurs only in leap years. The cumulative ranking reflects its fewer occurrences. The per-occurrence measure divides by its actual occurrences, without inserting zero-birth days into non-leap years.
- Ordering: the smallest values are shown first, with calendar date breaking ties. Lookup ranks use 1 for the most births and give equal values equal ranks. Displayed averages are rounded; sorting uses the unrounded values.
These are historical birth records, not the birthdays of all people alive today. They do not account for later migration or deaths. The counts alone do not establish why a date is more or less common.
Historical U.S. daily birth counts for 2000–2014, aggregated by month and day. This is not a distribution of the current U.S. population, is not a prediction, and does not explain causes. Total ranks favor dates that occurred more often in the period; daily-average ranks adjust for each date’s observed occurrences. Feb. 29 appears only in leap years.
Source and reuse
Contains data from FiveThirtyEight, “US births, 2000–2014 (SSA),” licensed under CC BY 4.0. Dataset documentation ↗ · Original CSV ↗ · CC BY 4.0 ↗
We grouped daily records into month/day totals, calculated averages and ranks, and built this presentation. No daily counts were changed. Source checked 2026-09-17.
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