March 17 is one of March's most common birthday dates in historical U.S. records. It ranks #2 within March and #171 among all 366 dates by total births from 1994 through 2014. Rank #1 means most common.
The files contain 234,700 births on March 17, a share of 0.274%, or about 1 in 365 recorded births. It ranks high within March and near the middle across the full year.
March 17, beside other birthdays
Average recorded births each time a date occurred, 1994 through 2014.
- Commonness rank
- 171 / 366
- Share of recorded births
- 0.274 %
- Recorded births
- 234,700
Bars start at zero. Rank 1 means most common and uses total births across all 366 dates. The bars use births per actual occurrence; February 29 appeared five times, while the other dates appeared 21 times.
Check March 17 and compare with a friend →How common is it beside other March birthdays?
March 17 has a higher total than March 16 and 18 in this sample. The same is true for the selected dates one week away and for March 31. The March birthday guide lists every date in the month, so you can compare beyond these neighbors.
| Date | Recorded births | Commonness rank | Birth share |
|---|---|---|---|
| March 10 | 230,444 | 248 | 0.269% |
| March 16 | 226,912 | 315 | 0.265% |
| March 17 | 234,700 | 171 | 0.274% |
| March 18 | 230,793 | 242 | 0.269% |
| March 24 | 229,992 | 259 | 0.268% |
| March 31 | 226,937 | 314 | 0.265% |
Each March 17 occurred once a year: 21 occurrences in the baseline. Dividing its total by those actual dates gives 11,176.2 recorded births per occurrence. That average describes the historical files, rather than the number born on March 17 this year.
Does March 17 stay higher after matching weekdays?
The annual study uses SSA U.S. records from 2000 through 2014. For each March 17, we compare March 3, 10, 24 and 31 in that same year. They are one or two weeks away and share the target's weekday. Matching weekdays matters because the weekday and weekend study finds large differences between days of the week.
We screen the control dates for actual and standard observed federal holidays, Christmas Eve, December 26 and the Friday after Thanksgiving. None of the March 17 candidates requires an exclusion, leaving 60 control dates across 15 years.
March 17 averages 11,173.9 births in this annual window, compared with 10,954.8 on its nearby comparison dates. The pooled difference is +2.0%. March 17 is above its comparison mean in all 15 years.
| Year | Weekday | Recorded births | Nearby mean | Difference |
|---|---|---|---|---|
| 2000 | Friday | 12,385 | 12,172.3 | +1.7% |
| 2001 | Saturday | 9,006 | 8,835.5 | +1.9% |
| 2002 | Sunday | 7,680 | 7,439.8 | +3.2% |
| 2003 | Monday | 11,990 | 11,895 | +0.8% |
| 2004 | Wednesday | 12,979 | 12,695 | +2.2% |
| 2005 | Thursday | 13,118 | 12,921 | +1.5% |
| 2006 | Friday | 13,003 | 12,913.5 | +0.7% |
| 2007 | Saturday | 8,791 | 8,670.8 | +1.4% |
| 2008 | Monday | 13,006 | 12,458 | +4.4% |
| 2009 | Tuesday | 13,542 | 13,319.5 | +1.7% |
| 2010 | Wednesday | 12,781 | 12,589.3 | +1.5% |
| 2011 | Thursday | 12,192 | 12,082 | +0.9% |
| 2012 | Saturday | 8,066 | 7,863.5 | +2.6% |
| 2013 | Sunday | 7,134 | 6,849.8 | +4.1% |
| 2014 | Monday | 11,936 | 11,616.5 | +2.8% |
The two comparison windows give similar results: +2.0% using only dates one week away, and +2.0% using only dates two weeks away. Both use all 15 years. We average each year's controls first, then divide summed target births by summed annual control means. Exact dates and counts appear in the downloadable analysis.
Does St. Patrick's Day explain the difference?
These are U.S. records. They do not measure how common a March 17 birthday is in Ireland. St. Patrick's Day is absent from the OPM list of U.S. federal holidays, so it is not a federal-holiday exclusion in this comparison.
The small excess in recorded births does not establish why it happened. Daily totals contain no information about parents' preferences, beliefs or delivery decisions. They support a historical count comparison, not a claim about a holiday causing more births.
Sources and your birthday comparison
The baseline uses birth records compiled by FiveThirtyEight: CDC/NCHS 1994 through 1999 plus SSA 2000 through 2014, with overlapping CDC years excluded. The annual study uses SSA alone because the source systems have different administrative coverage.
The share describes recorded births in that period. It cannot tell you how many living people share your birthday or how common the date is worldwide. Read the methodology, compare the full rarity ranking, or check another date in the birthday checker.