Holiday Calendar

National Jack Day

Next celebratedSunday, February 7, 2027

Jacks get a day whose best evidence sits in every deck of cards: when 'Kn' for knave proved too easy to confuse with 'K' for king, card makers took the name already meaning an ordinary man.

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Last updated August 18, 2026 · by the Holiday Calendar TeamHave an update or spot an error?
YEARLY DATEFebruary 7
OBSERVED INUnited States
CATEGORYNames
ORIGIN

Community Origin

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

A day the listings carry and nobody claims.

No documented founder or formal establishment record has been identified for National Jack Day. Its traceable footprint runs through holiday listings and dated social posts marking the day.

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

Kn to J: how an ordinary man got into every deck

National Jack Day keeps its best evidence in a deck of cards. Pull out the jack and look at the corner. The letter printed there is a compromise.

When card makers moved the index into the corners in the middle of the 1800s, Kn for knave and K for king were too easy to confuse. They needed a word that would not collide, and they took one already attached to the card and already meaning an ordinary man. The court cards have read K, Q and J ever since.

Jack keeps doing that. It started life as a nickname for John, then loosened into a word for anybody at all. Then it stepped off people altogether and onto their tools.

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ORIGINS

Jack Day history

INTRODUCTION

Jack and John share exactly one letter. For a long time that looked like proof of a French import. If Jack was not short for John, the reasoning went, it had to come from Jacques, which would quietly make every English Jack a James.

The record says otherwise, and it says so early.

CHAPTER 01

A Canterbury manuscript, 1414

The History of the Monastery of St Augustine at Canterbury noted in 1414 that the English reshape names, turning Johannes into Jankin or Jacke. Scholars trace the chain from the Latin Johannes through Jehan and Jan. The English suffix -kin gives Jankin, which nasalizes to Jackin and then shortens.

CHAPTER 02

The name that meant anybody

By 1450 Jack was already standing in for the ordinary man. The Coventry Mysteries of that year pair him with Gill, in a line the New English Dictionary later quoted: "Thow ther come both Iakke and Gylle."

Then the word did something stranger. Boys called Jack turned the roasting spit and pulled off their masters' boots, and when machines took over those jobs they took the name too. Isaac Watts wrote it down in his Logic of 1724, and the boot-jack and the meat-jack have carried it since.

CHAPTER 03

Settled in 1892, and still unclaimed

Edward W. B. Nicholson published his answer as a monograph in 1892. He showed, in the words of the reference work that reports him, that there is no recorded instance of Jack, Jak, Jacke, or Jakke ever being used to represent Jacques or James.

The French name descends from the Latin Iacobus and has always meant Jacob or James. The English Jack never did.

National Jack Day has nothing like that paper trail. It surfaces in holiday listings and in dated posts from people marking it. Nobody has put a name, an organisation or a year to the day itself.

TIMELINE

Timeline

Canterbury records Jack for John

A monastery history at Canterbury notes that the English turn Johannes into Jankin or Jacke.

Iakke and Gylle in print

The Coventry Mysteries pair Jack with Gill as the stock ordinary man and woman.

A clock jack at Reading

Parish accounts at St Lawrence Church call the figure that strikes the hours a jack.

Watts explains the boot-jack

Isaac Watts records that machines took over the work of foot boys called Jack, and their name.

Nicholson settles the Jacques question

His monograph finds no instance of Jack ever standing for Jacques or James.

Jack tops the England and Wales list

Jack ranked first among boys' names in the opening year of the annual series.

GOOD TO KNOW

Objects that took the name

The Union Jack

The Flag Institute says jack described a small flag flown from the bowsprit, and by 1627 a small Union Flag in that position was called the Jack.

The lifting jack

The 1911 Encyclopaedia Britannica calls a machine for raising weights from below the principal mechanical use of the word.

The jack in bowls

The small target bowl takes its name from the same sense of a thing smaller than the ordinary.

The telephone jack

Metal plugs used for connecting lines in a telephone exchange were already being called jacks by 1911.

The Jack Russell terrier

Britannica says the breed carries the name of the Rev. John 'The Sporting Parson' Russell, who bred it to hunt foxes.

BY THE NUMBERS

National Jack Day by the Numbers

24th
Jack's rank, England and Wales 2025
1,595
Boys named Jack, England and Wales 2025
100th
Jack's US rank for the 1990s
14th
Jack's US rank, 2020 to 2025
624,551
US boys named Jack, 1926 to 2025

WHY THIS DAY MATTERS

Why We Love National Jack Day

REGISTRIES

In Ireland the pet form now outranks its own source.

Ireland's Central Statistics Office ranked Jack second among boys' names for 2025. John, the name Jack was formed from, ranked 29th.

NAMESAKES

Two Jacks who were registered John

The JFK Presidential Library records that family and friends called John Fitzgerald Kennedy Jack from infancy. Britannica gives Jack London's birth name as John Griffith Chaney, so the novelist on the spine was a John too.

IDIOM

The everyday word outlived the fashion

Jack survives in English compounds where no particular person is being named, among them cheap-jack, steeple-jack and jack of all trades. Jack Tar, the old word for a sailor, appears to date from the 1600s.

GET INVOLVED

How to Celebrate National Jack Day

LOOK

Look up where the name ranks near you

Three national offices publish the tables, the ONS for England and Wales, the CSO for Ireland and the SSA for the United States. Pick the one that covers you and find the decade Jack peaked.

COUNT

Count the jacks in one room

A deck of cards, a car jack and a socket on the wall will usually do it. Say each one out loud and notice how little they have in common.

READ

Read the 1911 encyclopedia entry end to end

The 1911 entry on jack runs through black jacks, jack rafters, jack towels and the jack-boot. It is short, free to read and stranger than any summary of it.

POST

Post one jack with the day's hashtag

The day travels on social media under the tags NationalJackDay and JackDay. Photograph whichever jack you turned up and add the tag.

Test your knowledge

How well do you know National Jack Day?

1 / 8

Jack began as a pet form of which name?

Answer

No. It is an unofficial observance with no legal standing found in any country, so it is an ordinary working day.

COLOPHON

Sources

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

14sources
9primary records
7independently dated
Primary records
Office for National Statistics2026-07
Baby names for boys in England and Wales: 2025
Rank and count for every top-100 boys' name registered in England and Wales.
View source
Office for National Statistics2017
Baby names in England and Wales, 1996 to 2016
A workbook giving every name's rank and count year by year from 1996.
View source
U.S. Social Security Administration
Popular Names by Decade: the 1990s
The 200 most popular American boys' and girls' names of the 1990s, with counts.
View source
U.S. Social Security Administration
Popular Names for the period 2020 to 2025
Partial-decade American name rankings, covering six of the decade's ten years.
View source
U.S. Social Security Administration
Top Names Over the Last 100 Years
American name totals for births between 1926 and 2025, ranked by count.
View source
Central Statistics Office, Ireland2026-02
Irish Babies' Names 2025: Key Findings
Ireland's 2025 name rankings, with the statistician's note on Jack's long run.
View source
The Flag Institute
Union Jack or Union Flag?
The UK flag authority on the small bow flag that gave the Union Jack its name.
View source
John F. Kennedy Presidential Library and Museum
Life of John F. Kennedy
The library's own biography, including who the president was named for.
View source
Encyclopaedia Britannica (1911), via Wikisource1911
Jack
A full catalogue of the English senses of jack, from clock figures to jack-boots.
View source
Additional coverage
International Playing-Card Society
Why is the jack called a jack?
How the knave became the jack and why the corner index reads J.
View source
Dictionary of Medieval Names from European Sources2017-01
Why is Jack a nickname of John?
The standard reference answer, quoting Withycombe on Nicholson's 1892 finding.
View source
Oxford University Press, OUPblog2018-06
Etymology gleanings: May 2018, Part 2
Anatoly Liberman on Jankin, Jack, and what the French Jacques actually means.
View source
Encyclopaedia Britannica
Jack London
Biography of the novelist, including the name he was born with.
View source
Encyclopaedia Britannica2026-08
Jack Russell Terrier
Breed entry naming the sporting clergyman the terrier is called after.
View source
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