A leap year starting on Friday is any year with 366 days (i.e. it includes 29 February) that begins on

Friday Friday is the day of the week between Thursday and Saturday. In countries that adopt the traditional "Sunday-first" convention, it is the sixth day of the week. In countries adopting the ISO-defined "Monday-first" convention, it is the fifth day ...

1 January and ends on

Saturday Saturday is the day of the week between Friday and Sunday. No later than the 2nd century, the Romans named Saturday ("Saturn's Day") for the planet Saturn, which controlled the first hour of that day, according to Vettius Valens. The day's na ...

31 December. Its

dominical letter Dominical letters or Sunday letters are a method used to determine the day of the week for particular dates. When using this method, each year is assigned a letter (or pair of letters for leap years) depending on which day of the week the year star ...

s hence are CB. The most recent year of such kind was

2016 File:2016 Events Collage.png, From top left, clockwise: Bombed-out buildings in Ankara following the 2016 Turkish coup d'état attempt; the impeachment trial of Brazilian President Dilma Rousseff; Damaged houses during the 2016 Nagorno-Karabakh ...

and the next one will be

2044 In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 ( 21st to 30th centuries). Ongoing futures studies seek to understand what is ...

in the

Gregorian calendar The Gregorian calendar is the calendar used in most parts of the world. It was introduced in October 1582 by Pope Gregory XIII as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years dif ...

or, likewise,

2000 File:2000 Events Collage.png, From left, clockwise: Protests against Bush v. Gore after the 2000 United States presidential election; Heads of state meet for the Millennium Summit; The International Space Station in its infant form as seen from ...

and

2028 Predicted and scheduled events * January 1 – Books, films, and other works published in 1932 will enter the public domain in the United States. * January 12 – Partial lunar eclipse. * January 26 – Small annular solar eclip ...

in the obsolete

Julian calendar The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandr ...

. Any leap year that starts on Tuesday,

has only one

Friday the 13th Friday the 13th is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year. ...

: the only one in this leap year occurs in May. Common years starting on Saturday share this characteristic. In this leap year,

Martin Luther King Jr. Day Martin Luther King Jr. Day (officially Birthday of Martin Luther King, Jr., and sometimes referred to as MLK Day) is a federal holiday in the United States marking the birthday of Martin Luther King Jr. It is observed on the third Mond ...

is on

January 18 Events Pre-1600 * 474 – Seven-year-old Leo II succeeds his maternal grandfather Leo I as Byzantine emperor. He dies ten months later. * 532 – Nika riots in Constantinople fail. * 1126 – Emperor Huizong abdicates the Chi ...

Valentine’s Day Valentine's Day, also called Saint Valentine's Day or the Feast of Saint Valentine, is celebrated annually on February 14. It originated as a Christian feast day honoring one or two early Christian martyrs named Saint Valentine and, thro ...

is on a

Sunday Sunday is the day of the week between Saturday and Monday. In most Western countries, Sunday is a day of rest and a part of the weekend. It is often considered the first day of the week. For most observant adherents of Christianity, Sunday ...

Presidents Day Presidents' Day, also called Washington's Birthday at the federal governmental level, is a holiday in the United States celebrated on the third Monday of February to honor all persons who served as presidents of the United States and, since 1879 ...

is on its earliest possible date,

February 15 Events Pre-1600 * 438 – Roman emperor Theodosius II publishes the law codex Codex Theodosianus * 590 – Khosrau II is crowned king of Persia. * 706 – Byzantine emperor Justinian II has his predecessors Leontios and Tiberi ...

, the

leap day February 29, also known as leap day or leap year day, is a date added to leap years. A leap day is added in various solar calendars (calendars based on the Earth's revolution around the Sun), including the Gregorian calendar standard in mo ...

is on a

Monday Monday is the day of the week between Sunday and Tuesday. According to the International Organization for Standardization's ISO 8601 standard, it is the first day of the week and in countries that adopt the "Sunday-first" convention, it is ...

St. Patrick’s Day Saint Patrick's Day, or the Feast of Saint Patrick ( ga, Lá Fhéile Pádraig, lit=the Day of the Festival of Patrick), is a cultural and religious celebration held on 17 March, the traditional death date of Saint Patrick (), the foremost pat ...

and Cinco De Mayo is on a

Thursday Thursday is the Names of the days of the week, day of the week between Wednesday and Friday. According to the ISO 8601 international standard, it is the fourth day of the week. In countries which adopt the "Sunday-first" convention, it is the fi ...

Memorial Day Memorial Day (originally known as Decoration Day) is a federal holiday in the United States for mourning the U.S. military personnel who have fought and died while serving in the United States armed forces. It is observed on the last Monda ...

is on

May 30 Events Pre-1600 * 70 – Siege of Jerusalem: Titus and his Roman legions breach the Second Wall of Jerusalem. Jewish defenders retreat to the First Wall. The Romans build a circumvallation, cutting down all trees within fifteen kilometres ...

Juneteenth Juneteenth is a federal holiday in the United States commemorating the emancipation of enslaved African Americans. Deriving its name from combining "June" and "nineteenth", it is celebrated on the anniversary of General Order No. 3, i ...

is on a

U.S. Independence Day Independence Day (colloquially the Fourth of July) is a federal holiday in the United States commemorating the Declaration of Independence, which was ratified by the Second Continental Congress on July 4, 1776, establishing the United States ...

is on a Monday,

Labor Day Labor Day is a federal holiday in the United States celebrated on the first Monday in September to honor and recognize the American labor movement and the works and contributions of laborers to the development and achievements of the United St ...

is on

September 5 Events Pre-1600 * 917 – Liu Yan declares himself emperor, establishing the Southern Han state in southern China, at his capital of Panyu. * 1367 – Swa Saw Ke becomes king of Ava * 1590 – Alexander Farnese's army forces Hen ...

Halloween Halloween or Hallowe'en (less commonly known as Allhalloween, All Hallows' Eve, or All Saints' Eve) is a celebration observed in many countries on 31 October, the eve of the Western Christian feast of All Saints' Day. It begins the observanc ...

is on a Monday,

Thanksgiving Thanksgiving is a national holiday celebrated on various dates in the United States, Canada, Grenada, Saint Lucia, Liberia, and unofficially in countries like Brazil and Philippines. It is also observed in the Netherlander town of Leiden and ...

is on

November 24 Events Pre-1600 * 380 – Theodosius I makes his '' adventus'', or formal entry, into Constantinople. * 1190 – Conrad of Montferrat becomes King of Jerusalem upon his marriage to Isabella I of Jerusalem. *1221 – Genghis Khan d ...

, and

Christmas Christmas is an annual festival commemorating Nativity of Jesus, the birth of Jesus, Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people Observance of Christmas by country, around t ...

is on a Sunday. Additionally, this type of year is the only year that

does not fall on the penultimate Monday of February. In this type of year, all dates (except 29 February) fall on their respective weekdays 58 times in the 400 year Gregorian calendar cycle. Leap years starting on Sunday share this characteristic.

Calendars

Applicable years

Gregorian Calendar

Leap years that begin on Friday, along with those that start on Sunday, occur most frequently: 15 out of the 97 (≈ 15.46%) total leap years in a 400-year cycle of the

. Thus, the overall occurrence is 3.75% (15 out of 400). 400 year cycle century 1: 16, 44, 72 century 2: 112, 140, 168, 196 century 3: 208, 236, 264, 292 century 4: 304, 332, 360, 388

Julian Calendar

Like all leap year types, the one starting with 1 January on a Friday occurs exactly once in a 28-year cycle in the Julian calendar, i.e. in 3.57% of years. As the Julian calendar repeats after 28 years that means it will also repeat after 700 years, i.e. 25 cycles. The year's position in the cycle is given by the formula ((year + 8) mod 28) + 1).

References

{{DEFAULTSORT:Leap Year Starting On Friday Gregorian calendar Julian calendar Friday