What is the rarest birthday? December 25

About 6,546 births a year in the United States, 40% below an average day and 1.8 times fewer than September 9.

  1. Dec 25#366
  2. Jan 1#365
  3. Dec 24#364
  4. Jul 4#363
  5. Jan 2#362
A boy in a knitted sweater alone at a table with a tiny cake with one candle, snow falling outside the window
The bottom of the calendar

The twenty rarest birthdays

Seven of them are holidays; six more are the week of Thanksgiving.

  1. #366December 25 Christmas Day6,546−39.6%
  2. #365January 1 New Year's Day7,731−28.7%
  3. #364December 24 Christmas Eve7,994−26.3%
  4. #363July 4 Fourth of July8,692−19.9%
  5. #362January 29,123−15.9%
  6. #361December 269,215−15.0%
  7. #360November 26 Thanksgiving9,615−11.3%
  8. #359November 25 Thanksgiving9,648−11.0%
  9. #358November 24 Thanksgiving9,679−10.7%
  10. #357November 27 Thanksgiving9,739−10.2%
  1. #356October 31 Halloween9,798−9.7%
  2. #355November 28 Thanksgiving9,844−9.2%
  3. #354November 23 Thanksgiving9,902−8.7%
  4. #353February 29 Leap Day9,906−8.7%
  5. #352April 1 April Fools' Day10,016−7.6%
  6. #351December 2310,052−7.3%
  7. #350December 31 New Year's Eve10,151−6.4%
  8. #349July 510,294−5.1%
  9. #348January 1310,309−4.9%
  10. #347May 2710,322−4.8%
Things people get wrong

The famous answers, checked

Not the rarestFebruary 29#353 of 366 · −8.7%Leap Day happens every four years. On the days it happens it is rare, but thirteen dates see fewer births.
Rarer than its reputationOctober 31#356 of 366 · −9.7%Parents who can choose the day tend to skip Halloween. A mild dip, not a Christmas-scale shutdown.
Superstition, measuredThe 13th−1.7% against an average day, across all twelveThe 13th sees fewer births than the 12th and the 14th in every month of the year.
The reason

Why December 25

Nobody decides to be born on Christmas. Someone does decide when an induction or a caesarean is booked, and it is almost never a holiday.

  • Working days. A weekend day brings 27% fewer babies than a weekday, because scheduled deliveries are booked Monday to Friday. A holiday behaves like a Sunday, whatever day it falls on.
  • The whole cluster. Seven of the twenty rarest dates are holidays, and the days beside them follow: December 26 is #361 and January 2 is #362.
  • Not Leap Day. February 29 is famous for being rare, and counted on the years it happens it is: #353 of 366. But thirteen dates are rarer still, and the rarest of all are holidays.
At a glance

December 25 in numbers

The trough is the whole holiday fortnight: Christmas Eve and New Year's Day sit just above December 25, and December 27 to 30 fill up with the deliveries moved off the holidays, while December 26 and December 31 stay low.

December 25 is the floor of a holiday trough

December 25 · Christmas Day#366 of 366 · 6,546 births a year
1 in 605American babies are born on December 25
608,000Americans alive today were born on December 25, by our estimate
1.8×more births on September 9, the most common birthday
The mechanism

Births by day of the week

Inductions and planned caesareans are booked on working days, so the year has a weekly pulse. A holiday behaves like a Sunday, whatever day it falls on.

A weekend day brings 27% fewer babies than a weekday

Tuesday has the most births in the United States, about 11,628 a day; Sunday the fewest, about 7,838.

10,794
Mon
11,628
Tue
11,411
Wed
11,355
Thu
11,299
Fri
8,596
Sat
7,838
Sun
Around the world

Christmas is the rarest birthday in 16 of 27 countries

Elsewhere the rarest birthday is January 1 in Costa Rica, Ecuador, Hungary and Japan; December 26 in England & Wales, Ireland and the Netherlands; December 31 in Guatemala; December 24 in Denmark; November 1 in Slovenia; and February 29 in the Philippines.

PlaceRarest birthdayBirthdayBirths a yearBirthsRecords
Americas
United StatesDecember 256,546NCHS, 1989–⁠2024
ArgentinaDecember 25771DEIS, 2018–⁠2023
BrazilDecember 255,500DATASUS, 1997–⁠2024
ChileDecember 25428DEIS, 1990–⁠2017
Costa RicaJanuary 1131INEC Costa Rica, 2014–⁠2024
EcuadorJanuary 1525INEC, 2013–⁠2023
GuatemalaDecember 31670INE Guatemala, 2018–⁠2024
MexicoDecember 253,286INEGI, 2017–⁠2023
PeruDecember 25865INEI, 2019–⁠2025
Europe
BelgiumDecember 25197Statbel, 1992–⁠2025
DenmarkDecember 24110Statistics Denmark, 2007–⁠2025
England & WalesDecember 261,294ONS, 1995–⁠2025
FinlandDecember 2599Statistics Finland, 2010–⁠2025
FranceDecember 251,644INSEE, 1998–⁠2024
GermanyDecember 251,430Destatis, 2014–⁠2025
HungaryJanuary 1261KSH, 1970–⁠2020
IrelandDecember 26107CSO, 1980–⁠2023
LatviaDecember 2536CSB, 1996–⁠2025
NetherlandsDecember 26356CBS, 1995–⁠2025
NorwayDecember 25104SSB, 2011–⁠2025
PortugalDecember 25205INE Portugal, 1980–⁠2025
SloveniaNovember 138SURS, 2000–⁠2025
SwitzerlandDecember 25163FSO, 1969–⁠2025
Asia & Pacific
JapanJanuary 11,877e-Stat, 1996–⁠2025
MalaysiaDecember 251,232DOSM, 2000–⁠2022
New ZealandDecember 25117Stats NZ, 1980–⁠2023
PhilippinesFebruary 293,340PSA, 2006–⁠2024
The long list

The 100 rarest birthdays

Of the 100, 24 are January dates, 18 are April dates and 14 are February dates; seven of the twelve 13ths are among them.

  1. #366December 256,546
  2. #365January 17,731
  3. #364December 247,994
  4. #363July 48,692
  5. #362January 29,123
  6. #361December 269,215
  7. #360November 269,615
  8. #359November 259,648
  9. #358November 249,679
  10. #357November 279,739
  11. #356October 319,798
  12. #355November 289,844
  13. #354November 239,902
  14. #353February 299,906
  15. #352April 110,016
  16. #351December 2310,052
  17. #350December 3110,151
  18. #349July 510,294
  19. #348January 1310,309
  20. #347May 2710,322
  21. #346January 1510,327
  22. #345March 1310,340
  23. #344January 1610,345
  24. #343April 1310,368
  25. #342February 1310,375
  26. #341May 1310,376
  27. #340January 910,380
  28. #339January 2810,380
  29. #338January 810,387
  30. #337May 2610,387
  31. #336January 2910,391
  32. #335January 2110,393
  33. #334April 2910,396
  34. #333May 2910,401
  35. #332April 3010,401
  36. #331February 1910,414
  37. #330May 2810,429
  38. #329February 510,451
  39. #328April 910,457
  40. #327February 410,458
  41. #326January 710,461
  42. #325January 310,463
  43. #324January 2210,463
  44. #323January 3010,474
  45. #322February 1810,474
  46. #321February 2610,477
  47. #320November 2210,482
  48. #319May 3010,483
  49. #318December 910,483
  50. #317January 2710,490
  51. #316April 2810,492
  52. #315January 1410,492
  53. #314November 1310,493
  54. #313February 2510,495
  55. #312March 3110,496
  56. #311April 1510,500
  57. #310January 1910,503
  58. #309November 2910,505
  59. #308April 2310,507
  60. #307January 2010,513
  61. #306February 1710,516
  62. #305January 3110,518
  63. #304April 2110,520
  64. #303October 1310,521
  65. #302April 2210,531
  66. #301April 1410,536
  67. #300April 1610,537
  68. #299February 310,540
  69. #298March 2610,541
  70. #297April 810,542
  71. #296February 1110,546
  72. #295October 3010,547
  73. #294February 610,548
  74. #293March 1910,549
  75. #292February 2710,550
  76. #291April 710,552
  77. #290May 3110,555
  78. #289January 1710,558
  79. #288May 710,561
  80. #287March 1110,565
  81. #286December 1110,569
  82. #285May 610,571
  83. #284April 1010,575
  84. #283December 1010,576
  85. #282March 1210,577
  86. #281April 1710,578
  87. #280March 2510,578
  88. #279March 1810,580
  89. #278December 810,584
  90. #277February 2410,585
  91. #276March 510,590
  92. #275January 2310,601
  93. #274April 2410,601
  94. #273March 2710,602
  95. #272January 1010,606
  96. #271March 2410,610
  97. #270April 2710,613
  98. #269January 2610,615
  99. #268January 610,619
  100. #267March 610,622
Questions

Quick answers

What is the rarest birthday?

December 25, in the United States: about 6,546 births in an average year, −39.6% against an average day and 1.8 times fewer than September 9, the most common.

Is leap day the rarest birthday?

No, though it is rare. Counted on the days it actually happens, February 29 ranks #353 of 366, −8.7% against an average day. Christmas Day, New Year's Day, Christmas Eve and the Fourth of July all see fewer births on the days they happen.

Why are holidays the rarest birthdays?

Because so many births are scheduled. Inductions and planned caesareans are booked on working days, so a weekend day brings about 27% fewer babies than a weekday, and a holiday behaves like a Sunday whatever day it falls on. Seven of the twenty rarest dates are holidays.

Is Christmas the rarest birthday in every country?

Nearly. It is the rarest birthday in 16 of the 27 countries we hold records for. Elsewhere the rarest birthday is January 1 in Costa Rica, Ecuador, Hungary and Japan; December 26 in England & Wales, Ireland and the Netherlands; December 31 in Guatemala; December 24 in Denmark; November 1 in Slovenia; and February 29 in the Philippines.

What is the most common birthday?

September 9, with about 11,900 births a year in the United States. The top of the calendar is a slope through September, nine months after the winter holidays.

So, how rare is yours?

Find your dateJanuary
12345678910111213141516171819202122232425262728293031

Every one of the 366 dates counted the same way. How we count.