Holiday Calendar
Your holidays

National Brittany Day

Next celebratedTuesday, September 21, 2027

Brittany is a French peninsula that has given the name to roughly 655 French girls since 1900, and to 360,673 American ones. September 21 belongs to an American name about a French place.

Countdown to the day
--DAYS
--HRS
--MIN
--SEC
Last updated September 7, 2026 · by the Holiday Calendar TeamHave an update or spot an error?
YEARLY DATESeptember 21
OBSERVED INInternationally
CATEGORYNames
ORIGIN

Community Origin

FOUNDING ENTITY
Not documented
FIRST OBSERVED
~2022
HOW THE HOLIDAY CAME TO BE

Traced to a 2022 listing, since removed.

No founder, sponsor, or establishing record for National Brittany Day has been located. The earliest traceable circulation is a holiday-registry listing first captured by the Internet Archive on 2 September 2022, and that listing has since been taken down.

+ Know the story? Submit a founder Help us complete this holiday
INTRO

Counting the Brittanys in France since 1900

Brittany is a region of France. The name is barely used there: across every birth year from 1900 to 2025, INSEE's national file records roughly 655 French girls given it. National Brittany Day is for the name, not the region.

The American figure is of another order. The Social Security Administration's national baby-name data counts 360,673 girls named Brittany.

Set the two counts side by side and one description fits: an American name about a French place. The registries supply the counts and the dates, and stop there.

Advertisement
ORIGINS

Brittany Day history

INTRODUCTION

The peninsula came first. Julius Caesar conquered it in 56 BCE, and the region became part of the Roman Empire as Armorica, a Romanization of the Celtic words for seaside. Its modern name arrived later, with people crossing the channel.

Celts from Britain moved into the area during the fifth and sixth centuries to escape the Anglo-Saxon invaders. Britannica puts it plainly: it is from this event that Brittany derives its name.

CHAPTER 01

From duchy to French province

The peninsula was first united in the 800s under Nomenoë. In the following century its ruler took the title of duke, with a capital at Rennes.

It became French through two marriages. Anne, heir to Brittany, married Charles VIII and then Louis XII, two successive kings of France. The formal treaty of incorporation in 1532 guaranteed the province its local privileges.

CHAPTER 02

All but unknown, then everywhere

The name reached American birth certificates much later. Etymonline records that as a girls' name, variously spelled, it was all but unknown in the US before 1970.

The federal data puts a floor under that. 1963 is the first year Brittany clears the Social Security Administration reporting threshold, with 7 girls. It entered the American top ten in 1986 and stayed there for ten consecutive years, through 1995.

CHAPTER 03

What the French file shows

France's own record of the name is short. The first year INSEE reports a count is 1989.

The French figure peaks at about 75 in 1994. By 2025 it is down to about 5.

CHAPTER 04

Where the day comes in

Against a record that long, National Brittany Day is very short. No author, sponsor or proclamation for it has turned up, and its earliest traceable appearance is a registry listing captured in September 2022.

TIMELINE

Timeline

Caesar takes the peninsula

The region became part of the Roman Empire as Armorica, a Romanization of the Celtic words for seaside.

A treaty binds Brittany to France

The formal treaty of incorporation guaranteed the province its local privileges.

Brittany clears the US reporting threshold

Seven girls were given the name, the first year it clears the Social Security Administration reporting floor.

The name enters America's top ten

It stayed inside the top ten for ten consecutive years, through 1995.

France reports its first count

INSEE's national file shows French girls with the name for the first time.

The earliest listing is archived

The Internet Archive captured a holiday-registry listing for National Brittany Day in September.

BY THE NUMBERS

National Brittany Day by the Numbers

37,792
US girls named Brittany, 1989
#3
Brittany's peak US name rank, 1989
281
US girls named Brittany, 2025
#928
Brittany's US name rank, 2025

GOOD TO KNOW

Surprising facts about National Brittany Day

Spears was named near the foot of the wave

Britney Spears was born on 2 December 1981. That year the spelling Britney ranked 760th in the United States, with 217 girls.

A spelling that fell for eight years, then spiked

Britney went from 2,294 girls in 1990 down to 572 in 1998, then rose to 1,495 in 1999 and to 2,404 in 2000, its highest year since 1989, before falling again every year through 2010. Spears released her first single in 1998, and the album that followed in 1999 went to number one.

The Brittany dog lost half its name in 1982

The American Kennel Club dropped the word spaniel from the breed's name, after the American breed fancy determined the dogs are less flushing dogs like spaniels and more of a pointing breed. In France the breed is still called l'epagneul Breton.

The day's one registry listing was taken down

Of the three holiday registries checked against the Internet Archive, two never carried the day at any point, though their pages for other holidays are archived from 2015 and 2018. The third carried it from September 2022 and had dropped it sometime between May 2024 and July 2025.

Brittany was most of a whole family of names

A mechanical prefix rule counts every female name in the federal file beginning with the letters Brit: 128 of them appear across 1880 to 2025, and 83 in 1989 alone. Those 83 names covered 54,986 births that year, and Brittany itself was 68.7% of the total.

WHY THIS DAY MATTERS

Why National Brittany Day Matters

LANGUAGE

Yann, Erwan and Ronan fill the French registers. Brittany does not.

INSEE counts about 86,905 boys named Yann in France since 1900, and about 40,645 named Erwan. The near absence of Brittany itself is therefore not a case of French parents avoiding the region's naming stock.

MEASURE

The two national counts are not one measure

INSEE rounds every French count to the nearest multiple of five and lists only names given at least three times since 1900, while the Social Security Administration suppresses any name given fewer than five times in a year. Two different censoring rules and two different population bases are why the French and American counts here sit side by side rather than as a ratio.

GET INVOLVED

How to Observe National Brittany Day

READ

Read how the peninsula got its name

The Britannica history of the region runs from Caesar's conquest to the 1532 treaty of incorporation. Read it straight through rather than skipping to the naming.

COMPARE

Compare the French record with the American one

France's national name file is published by INSEE and covers births from 1900 onward. Pull Brittany out of it, then pull the same name out of the American file and set the two beside each other.

RECOGNIZE

Recognize a Brittany you know

This is a name day, so the observance is mostly personal. A note to someone named Brittany on September 21 is the whole of it.

Test your knowledge

How well do you know National Brittany Day?

1 / 9

Which group gave the region of Brittany its name?

Answer

No. It is an unofficial observance: a Federal Register search for the exact phrases National Brittany Day and Brittany Day returns zero US federal documents, so September 21 is a normal working day.

COLOPHON

Sources

How we know what’s on this page. References, not endorsements.

8sources
5primary records
3independently dated
Primary records
U.S. Social Security Administration2025
National baby names data, years of birth 1880 to 2025
Every first name given to US babies, by birth year and sex, with a five-birth floor.
View source
Institut national de la statistique et des etudes economiques2025
Fichier des prenoms (prenoms-2025-nat)
First names given in France from 1900 onward, counted by sex and birth year.
View source
American Kennel Club
Facts About the Brittany That You May Not Know
The registry's own account of dropping spaniel from the breed name in 1982.
View source
U.S. Federal Register
Documents search API
Search API for documents published in the US Federal Register.
View source
Internet Archive
Wayback CDX Server API
Capture history for any archived web address, queried by URL and date.
View source
Additional coverage
Online Etymology Dictionary
Brittany
Word history of Brittany from Old French Bretaigne, plus a note on the girls' name.
View source
Encyclopaedia Britannica2026-08
History of Brittany
The region from Caesar's conquest through the dukes to the 1532 union with France.
View source
Encyclopaedia Britannica
Britney Spears
Biography covering her 1981 birth, the 1998 single, and the 1999 debut album.
View source
YOU MIGHT ALSO LIKE

Related holidays

SUN
25
Oct 2026
National Danielle Day
Names

National Danielle Day

National Danielle Day marks a French name that English took up late and then took up hard. Underneath the spelling is a small Hebrew sentence, dan for judge and El for God, which the name has been saying all along.

48Read
THU
28
Jan 2026
National Amy Day
Names

National Amy Day

Amy does not merely suggest beloved; grammatically it is the word, the Old French past participle of amer, to love. Its day goes to a name that spent four straight years as America's number two, always behind Jennifer.

148Read
SAT
07
Nov 2026
National Lori Day
Names

National Lori Day

A day for the Loris, whose name outranked the Laura it supposedly shortens: across the 1960s, 176,560 American girls were named Lori to Laura's 174,185.

126Read
FOR MARKETERS & CREATORS

Turn every day into a moment your audience actually shows up for.

8.4M
Monthly readers
5K+
Holidays tracked
Holiday Calendar for Brands Developer API