🎂 Rarest Birthdays: All 366 Days Ranked (2026 Data)
Why Some Birthdays Are Rarer
The distribution of birthdays across the year is not random. Three key factors create predictable patterns: scheduled C-sections and inductions (about 1 in 3 US births) are rarely scheduled on holidays or weekends, the holiday season in November-December drives higher conception rates creating the September birth peak, and cultural factors like avoiding births on dates perceived as unlucky (April 1, September 11 post-2001) create additional dips.
The 20 Rarest Birthdays (US Data)
Ranked by average annual births. Data from CDC/FiveThirtyEight analysis of US births 1994–2014.
| # | Date | Avg Births | Reason |
|---|---|---|---|
| 1 | February 29 | ~1,000* | Leap Day — only exists every 4 years |
| 2 | December 25 | 6,574 | Christmas Day — no scheduled procedures |
| 3 | January 1 | 7,792 | New Year's Day |
| 4 | December 24 | 8,069 | Christmas Eve |
| 5 | July 4 | 8,796 | Independence Day |
| 6 | January 2 | 9,307 | Day after New Year's |
| 7 | December 26 | 9,543 | Day after Christmas |
| 8 | November 27 | 9,718 | Near Thanksgiving (floating) |
| 9 | November 23 | 9,883 | Near Thanksgiving (floating) |
| 10 | October 31 | 9,978 | Halloween |
| 11 | November 25 | 9,954 | Near Thanksgiving |
| 12 | December 31 | 10,080 | New Year's Eve |
| 13 | January 3 | 10,156 | Post-holiday slowdown |
| 14 | November 28 | 10,200 | Near Thanksgiving |
| 15 | November 24 | 10,245 | Near Thanksgiving |
| 16 | April 1 | 10,312 | April Fool's Day — cultural avoidance |
| 17 | November 22 | 10,356 | Near Thanksgiving |
| 18 | December 27 | 10,402 | Holiday week |
| 19 | January 4 | 10,456 | Post-holiday |
| 20 | December 23 | 10,510 | Pre-Christmas slowdown |
The September Phenomenon
Nine of the ten most common birthdays fall between September 9 and September 20. This isn't coincidence — counting back 9 months lands squarely in the December holiday season, when couples spend more time together indoors. Research also suggests male fertility peaks in colder months with improved sperm quality. The one non-September date in the top 10 is July 7, likely due to post-Independence Day scheduling of delayed procedures.
Leap Day Babies: The Rarest of All
People born on February 29 — called "Leaplings" or "Leapers" — have a 1 in 1,461 chance of being born on that date. Roughly 5 million people worldwide have a February 29 birthday. In non-leap years, Leaplings typically celebrate on either February 28 or March 1, with no universal standard. Some countries legally assign March 1, while others use February 28. Leap Day babies include motivational speaker Tony Robbins and rapper Ja Rule.
Birthday Rarity Around the World
Birthday patterns differ by country based on local holidays and cultural factors:
In Japan, the rarest birthday is January 1 (very few scheduled births on New Year's). The most common falls in late September, similar to the US pattern.
In India, birth timing correlates with auspicious dates in the Hindu calendar. Some families specifically request C-sections on dates considered lucky.
In UK, the pattern mirrors the US with Christmas Day as the rarest and late September as the peak, though September 26 is the UK's most common birthday.
In Turkey, January 1 shows an unusual spike because births with unknown dates are officially recorded as January 1, making it appear artificially common.
⭐ Surprising Birthday Facts
Related Rarity Guides
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🎲 The Birthday Paradox: Rarity's Famous Illusion
Your birthday feels rare — 1 of 366 days — yet in any group of just 23 people, the odds that two share a birthday already pass 50%. At 70 people it exceeds 99.9%. The trick is that matches can occur between any pair, and 23 people contain 253 pairs. It is the cleanest everyday proof that human intuition systematically underestimates combination math — the same math that makes your full trait combination rarer than any single trait suggests.
📅 Exact-Date Twins: Sharing Your Full Birthdate
Sharing a day-and-month is common; sharing the complete date — day, month, and year — is a different game. With roughly 385,000 births worldwide per day, about that many people entered life on your exact date, of whom (depending on your cohort's age) a few hundred thousand are alive today. They are your statistical twins: every one of them shares your zodiac sign, your generation, and your age to the day — and almost nothing else, which is rather the point of this entire site.
Frequently Asked Questions
How many people share my exact birthdate including the year?
Roughly 300,000–400,000 people worldwide were born on your exact date; allowing for mortality, several hundred thousand are alive now for most readers' cohorts.
Why do so few babies arrive on holidays?
Scheduled inductions and C-sections — over 30% of deliveries in many countries — are almost never booked on Christmas, New Year's, or July 4th. Hospitals quietly move those births to adjacent days, carving permanent notches into the calendar.