Why is Morse Code Day on April 27?

Because it is Samuel Morse's birthday: the Library of Congress dates his birth to April 27, 1791, in Charlestown, Massachusetts. The day's own beginnings are a different matter, since no founder, year or establishing document for the observance could be located.

Who invented Morse code?

That is genuinely disputed. Alfred Vail's own 1845 book credits the alphabet to Samuel Morse, Morse claimed it himself in his report on the Paris Exhibition of 1867, Vail's son published his father's papers in 1914 to argue the opposite, and the Library of Congress and the Smithsonian Institution Archives still describe the same 1838 change differently.

Is Morse Code Day the same as World Amateur Radio Day?

No, they are nine days apart and mark different things. World Amateur Radio Day falls on April 18 and marks the founding of the International Amateur Radio Union in Paris in 1925.

Morse Code Day

Next celebratedTuesday, April 27, 2027

Morse code was still gaining letters in the 2000s: between 1998 and 2004 the ITU added the at sign, the one in the middle of an email address. April 27 marks a code that is not quite the one Morse's own line ran.

See how to celebrate

Countdown to the day

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Last updated September 6, 2026 · by the Holiday Calendar TeamHave an update or spot an error?

YEARLY DATEApril 27

OBSERVED INInternationally

CATEGORYTech

SUBCATEGORYSoftware

ORIGIN

Community Origin

FOUNDING ENTITY

Not documented

FIRST OBSERVED

Not documented

“The Library of Congress dates Samuel Morse's birth to April 27, 1791. The day named for his code carries no such record.

HOW THE HOLIDAY CAME TO BE

A birthday on record, an observance without one.

No founder, inception year or establishing document for Morse Code Day could be located. What the record does supply is the reason for the date: the Library of Congress dates Samuel Finley Breese Morse's birth to April 27, 1791, in Charlestown, Massachusetts.

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INTRO

The at sign arrives in a telegraph alphabet

In March 1998 the International Telecommunication Union published the rules for sending a telegram by Morse, and its list of characters stopped at the multiplication sign. By May 2004 the same body's Morse text carried one more entry at the bottom of the list: the commercial at sign, the symbol in the middle of an email address. Morse Code Day is a day for a code that was still gaining characters in the 2000s.

That is easy to miss, because the code is usually filed under history. The union's 2009 recommendation on international Morse code sets out the characters and the exact timing an operator has to keep. It also records where use continues: the amateur and amateur-satellite services, and, in the union's own words, to a diminishing extent in the mobile and fixed services.

The other thing the standard shows, read beside Alfred Vail's 1845 account of the working line, is that it is not quite the code Samuel Morse's own line ran. The gap between two words was six dots on the line that ran from Washington to Baltimore. In the international standard it is seven.

GOOD TO KNOW

Surprising facts about Morse Code Day

The rules never spelled out the letters

Article XVI of the 1906 Berlin service regulations prints the ship distress signal as dots and dashes, and so does the US Radio Act of 1912. The IMO says the familiar letters are not an abbreviation and have no special significance beyond being easy to remember and send.

The ITU says the first networks were in England

The ITU's own history records that the first networks were installed in England by William Fothergill Cooke and Charles Wheatstone, and that Samuel Morse opened a network in the United States in 1844.

Silence was part of the old alphabet

Leonard Gale, testifying under oath in Morse v. O'Reilly in August 1848, described the alphabet of Morse as consisting of horizontal dashes, dots and spaces. He listed the pause alongside the marks, as one of the three things the alphabet was made of.

More than 3,800 comments reached the FCC

Before the Commission removed the five words per minute telegraphy examination in 2007, its own order records, over 3,800 comments arrived on the proposed rule changes.

A society formed the day the keys went quiet

The Maritime Radio Historical Society says it was formed on 12 July 1999, which it calls the date of the supposed last commercial Morse transmission in the US. Its founders went to the KPH sites expecting vandalism and found an intact radio time capsule, the receivers still on, keeping watch on the Morse calling channels.

ORIGINS

Morse Code Day history

INTRODUCTION

The moment the code became an alphabet has a month attached to it. In January 1838 the telegraph stopped sending numbers looked up in a word dictionary and began sending a pattern for each letter. Who worked that out is contested.

CHAPTER 01

Whose alphabet was it

Alfred Vail and Samuel Morse left records pointing in opposite directions. Vail's own book of 1845 says the alphabet "was originated on board the packet Sully, by Prof. Morse", while Morse's report on the Paris Exhibition listed "the dot and line alphabet" among his own inventions. Vail's son published his father's letters in 1914 to argue the other way.

The disagreement did not end with them. The Library of Congress credits Morse with the change, from a telegraphic dictionary to a code for each letter. The Smithsonian Institution Archives, which holds Vail's papers, credits Vail with a simpler alphabetic system to replace Morse's numerical one, and notes that Morse's name went on the patents.

CHAPTER 02

Two codes, one name

Vail's book also describes the code the Washington to Baltimore line actually ran, and it is not the code the ITU's recommendation sets out. A touch about four dots long was the mark for L, and one about six dots long the mark for zero. The recommendation gives the dash a single length, three dots, and spells both letters out of dots and dashes.

Encyclopaedia Britannica records that the original American code is hardly in use today, though the American telegraph industry kept it until teleprinters took over. The two versions still agree on one thing: three dots separate letters in both, and the international code is a revision of the American one rather than a rival to it.

CHAPTER 03

The day itself

Morse Code Day has nothing like that paper trail. No founder, year or establishing document turns up for it, and the earliest archived page about it that turned up dates from 2012. What is documented is the date: the Library of Congress records Samuel Finley Breese Morse's birth in Charlestown, Massachusetts, on April 27, 1791.

The Library's record of the man covers more than wires: it lists his 1835 book Foreign Conspiracy Against the Liberties of the United States, described there as a treatise against the political influence of Catholicism. He ran for mayor of New York the next spring for a nativist party, taking 1,496 votes.

TIMELINE

Timeline

A code for each letter

In January the telegraph switches from a numbered dictionary of words to a code for each letter, removing the need to encode and decode every word.

What hath God wrought

On 24 May the message travels from the Supreme Court chamber in the Capitol to the railroad depot in Baltimore.

Morse code written into treaty

Twenty countries sign the first International Telegraph Convention in Paris, and its service regulations require the adoption of Morse code and its instruments.

Ships get one distress signal

The Berlin radiotelegraph convention tells ships in distress to send three dots, three dashes and three dots, repeated at brief intervals.

Morse leaves the shipping lanes

On 1 February the Global Maritime Distress and Safety System becomes fully operational and Morse code is phased out at sea.

America drops the code test

On 23 February the removal of the five words per minute telegraphy examination for two US amateur licence classes takes effect.

Morse will carry on in other parts of the world even after the keys in North America are finally silent.

Richard DillmanMaritime Radio Historical Society, present at the 1999 sign-off

WHY THIS DAY MATTERS

Why Morse Code Day Matters

SAFETY

One agreed pattern, and the traffic stopped for it

From the Berlin regulations of 1906 a ship in distress had one agreed pattern to send, and a station that heard it had to stop its own traffic and, unless the call named another station, answer. That same pattern was still the distress signal at sea until the Global Maritime Distress and Safety System became fully operational in 1999.

SKILL

Working the code was a full trade

The IMO's account of the old maritime radio system lists specialization among its limits: Morse telegraphy required many years of training and practice. If something happened to the radio operator, it was unlikely that anyone else on board would be able to use the telegraphy equipment.

KEEPING

Whoever keeps the day decides what it is

Because the day is kept by whoever chooses to keep it, what happens on it comes from individual institutions rather than a central campaign. The Museum of Maritime Navigation and Communication in Staten Island posted that it marked National Morse Code Day on April 27 in 2020, in the middle of the COVID-19 crisis, with an online Morse game.

GET INVOLVED

How to Observe Morse Code Day

Learn the timing, not just the letters

Most charts give the dots and dashes and stop there, though the standard fixes the silences as well. Set your spacing from the ITU's own recommendation on international Morse code rather than by feel.

COMPARE

Compare how two institutions tell the same story

Read the Library of Congress timeline for January 1838 and then the Smithsonian Institution Archives on Alfred Vail. They describe the same change and hand the credit to different men.

SEND

Send your own name in dots and dashes

Work it out by hand from the character table rather than a translator, keeping the gaps to the lengths the standard sets. The gaps are specified as precisely as the marks are.

LISTEN

Listen for a station that still keys Morse

The Maritime Radio Historical Society operates the former coast stations KPH and KFS at Bolinas and Point Reyes. Its Night of Nights transmission runs every 12 July, opening at 5:01pm Pacific time.

READ

Read the 1906 distress rule in the original

The ITU's library has scanned the Berlin convention of 1906, service regulations included. Article XVI is where the signal itself is set out.

Test your knowledge

How well do you know Morse Code Day?

1 / 7

Why does Morse Code Day fall on April 27?

Answer

No. It is an unofficial observance with no legal standing found, so it is a normal working day. A search of the Federal Register's full-text index, which runs from 1994, returns nothing for either Morse Code Day or National Morse Code Day.

COLOPHON

Sources

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

20sources

15primary records

11independently dated

Primary records

Library of Congress

Samuel F. B. Morse Papers: Timeline, 1791 to 1839

Dated entries for Morse's birth, his nativist mayoral run and the 1838 letter code.