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

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, Sund ...

, 1 January, and ends on

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 t ...

, 31 December. Its dominical letters hence are AG. The most recent year of such kind was

2012 File:2012 Events Collage V3.png, From left, clockwise: The passenger cruise ship Costa Concordia lies capsized after the Costa Concordia disaster; Damage to Casino Pier in Seaside Heights, New Jersey as a result of Hurricane Sandy; People gat ...

and the next one will be 2040 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 d ...

or, likewise,

1996 File:1996 Events Collage.png, From left, clockwise: A bomb explodes at Centennial Olympic Park in Atlanta, set off by a radical anti-abortionist; The center fuel tank explodes on TWA Flight 800, causing the plane to crash and killing everyone o ...

and 2024 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 Alexandri ...

. This is the only leap year with three occurrences of

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. ...

: those three in this leap year occur three months (13 weeks) apart: in January,

April April is the fourth month of the year in the Gregorian and Julian calendars. It is the first of four months to have a length of 30 days, and the second of five months to have a length of less than 31 days. April is commonly associated with ...

, and

July July is the seventh month of the year in the Julian and Gregorian calendars and is the fourth of seven months to have a length of 31 days. It was named by the Roman Senate in honour of Roman general Julius Caesar in 44 B.C., it being the mont ...

. Common years starting on Thursday share this characteristic, in the months of February, March, and November. In this leap year, Martin Luther King Jr. Day is on

January 16 Events Pre-1600 * 27 BC – Gaius Julius Caesar Octavianus is granted the title Augustus by the Roman Senate, marking the beginning of the Roman Empire. * 378 – General Siyaj K'ak' conquers Tikal, enlarging the domain of King Sp ...

;

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, thr ...

is on a

Tuesday Tuesday is the day of the week between Monday and Wednesday. According to international standard ISO 8601, Monday is the first day of the week; thus, Tuesday is the second day of the week. According to some commonly used calendars, however ...

; Presidents' Day is on

February 20 Events Pre-1600 *1339 – The Milanese army and the St. George's (San Giorgio) Mercenaries of Lodrisio Visconti clash in the Battle of Parabiago; Visconti is defeated. * 1472 – Orkney and Shetland are pawned by Norway to Scotlan ...

; 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 m ...

is on a

Wednesday Wednesday is the day of the week between Tuesday and Thursday. According to international standard ISO 8601, it is the third day of the week. In countries which have Friday as their holiday, Wednesday is the fifth day of the week. In countrie ...

;

Saint 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 patr ...

is on a

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 da ...

;

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 28 Events Pre-1600 *585 BC – A solar eclipse occurs, as predicted by the Greek philosopher and scientist Thales, while Alyattes is battling Cyaxares in the Battle of the Eclipse, leading to a truce. This is one of the cardinal dates from ...

;

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 is on a Wednesday;

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 3 Events Pre-1600 *36 BC – In the Battle of Naulochus, Marcus Vipsanius Agrippa, admiral of Octavian, defeats Sextus Pompey, son of Pompey, thus ending Pompeian resistance to the Second Triumvirate. * 301 – San Marino, one of t ...

; Columbus Day is on its earliest possible date, October 8;

Election Day Election day or polling day is the day on which general elections are held. In many countries, general elections are always held on a Saturday or Sunday, to enable as many voters as possible to participate; while in other countries elections ...

in the USA is on November 6th;

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 observan ...

is on a Wednesday;

Veterans Day Veterans Day (originally known as Armistice Day) is a federal holiday in the United States observed annually on November 11, for honoring military veterans of the United States Armed Forces (who were discharged under conditions other than dis ...

is on a

;

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 ...

is on its earliest possible date,

November 22 Events Pre-1600 * 498 – After the death of Anastasius II, Symmachus is elected Pope in the Lateran Palace, while Laurentius is elected Pope in Santa Maria Maggiore. * 845 – The first duke of Brittany, Nominoe, defeats the Fr ...

; and

Christmas Christmas is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world. A feast central to the Christian liturgical year ...

is on a

. 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 Friday share this characteristic.

Calendars

Applicable years

Gregorian Calendar

Leap years that begin on Sunday, along with those that start on Friday, 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: 12, 40, 68, 96 century 2: 108, 136, 164, 192 century 3: 204, 232, 260, 288 century 4: 328, 356, 384

Julian Calendar

Like all leap year types, the one starting with 1 January on a Sunday 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, it will also repeat after 700 years, i.e., 25 cycles. The formula gives the year's position in the cycle ((year + 8) mod 28) + 1).

References

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