What was the most common birthday in 2004?

Published by Birthday Traffic · September 15, 2026 · Sources and method

September 9most births in 2004a Thursday, 14,526 births
December 25fewest births in 2004a Saturday, 6,259 births
Septemberbusiest month per day12,097 births per day
Tuesdaybusiest weekday13,309 per day against 7,611 on Sunday

In 2004 the United States recorded 4,186,863 births over 366 days, 11,440 on an average day. The busiest single date was September 9, a Thursday, with 14,526 births; the quietest was December 25, a Saturday, with 6,259. Within one year every date has one weekday, so the weekday column below is a fact of that date. 2004 is a leap year, so February 29 is one of its 366 days.

Every day of 2004: recorded U.S. births

Every day of 2004 in calendar order as one line, with the busiest and quietest dates marked and the year’s average day drawn across it.

The regular dips are weekends. The deepest dips are fixed holidays.

The busiest dates of 2004

Dates of 2004 with the most recorded U.S. births
Date	Weekday	Births	% of an average day
September 9	Thursday	14,526	127.0
July 7	Wednesday	14,496	126.7
September 8	Wednesday	14,492	126.7
December 21	Tuesday	14,390	125.8
November 23	Tuesday	14,238	124.5
September 14	Tuesday	14,172	123.9
September 10	Friday	14,081	123.1
July 8	Thursday	14,056	122.9
September 23	Thursday	13,969	122.1
December 28	Tuesday	13,965	122.1

The quietest dates of 2004

Dates of 2004 with the fewest recorded U.S. births
Date	Weekday	Births	% of an average day
December 25	Saturday	6,259	54.7
April 11	Sunday	6,969	60.9
December 26	Sunday	7,087	62.0
February 1	Sunday	7,270	63.6
February 29	Sunday	7,301	63.8
March 7	Sunday	7,304	63.8
January 11	Sunday	7,316	64.0
January 4	Sunday	7,359	64.3
May 9	Sunday	7,380	64.5
March 14	Sunday	7,401	64.7

2004 by weekday and by month

Weekend days in 2004 recorded 64% of a weekday’s births per day. The quietest dates above are mostly weekend days and fixed holidays; the busiest are weekdays in late summer. The counts show the association.

2004: births per day by weekday

Seven columns, Monday to Sunday, average recorded births per day in 2004.

2004: births per day by weekday
Weekday	Days	Births per day
Tuesday	52	13,309
Wednesday	52	13,117
Thursday	53	12,877
Friday	53	12,557
Monday	52	11,928
Saturday	52	8,628
Sunday	52	7,611

2004: births per day by month
Month	Births	Births per day
September	362,895	12,097
July	365,380	11,786
June	350,876	11,696
August	361,835	11,672
October	355,048	11,453
November	342,359	11,412
December	353,339	11,398
March	352,379	11,367
April	339,079	11,303
February	321,348	11,081
May	343,248	11,073
January	339,077	10,938

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Sources, method and limits

Source for 2004: Social Security Administration daily births for the United States, as compiled by FiveThirtyEight (CC BY 4.0). The 2000–2003 overlap between the two files is taken from the SSA file only. Weekday is taken from the record’s calendar date. Ranks within a year compare single days.

Every figure above comes from the administrative records named here, at the granularity those records publish: a day, a month or a year. Coverage and definitions differ between countries and eras, so two sources are combined only where their documentation states the windows are separate, and the page where that happens says so.

Full method, leap-day treatment and definitions.

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