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

, 1 January, and ends on

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 ...

, 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 sta ...

s hence are GF. The most recent year of such kind was 1996 and the next one will be 2024 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, 2008, and 2036 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

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 ...

Thursday Thursday is the 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 fifth day of the week. Name ''Se ...

has two Friday the 13ths: those two in this leap year occur in September and

December December is the twelfth and final month of the year in the Julian and Gregorian calendars and is also the last of seven months to have a length of 31 days. December got its name from the Latin word ''decem'' (meaning ten) because it was or ...

. Common years starting on Tuesday 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 its earliest possible date, January 15;

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

;

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 February 19; 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

;

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 Sunday;

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 27,

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 ...

and Halloween are on a Thursday;

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 latest possible date,

November 28 Events Pre-1600 * 587 – Treaty of Andelot The Treaty of Andelot (or Pact of Andelot) was signed at Andelot-Blancheville in 587 between King Guntram of Burgundy and Queen Brunhilda of Austrasia. Based on the terms of the accord, Brun ...

; and

Christmas Day 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

. The Election Day in the USA is on November 5th, as well in common years starting on Tuesday.

Calendars

Applicable years

Gregorian Calendar

Leap years that begin on Monday, along with those that start on Saturday or

, occur least frequently: 13 out of 97 (≈ 13.402%) total leap years of the

. Their overall occurrence is thus 3.25% (13 out of 400). 400 year cycle century 1: 024, 052, 080 century 2: 120, 148, 176 century 3: 216, 244, 272 century 4: 312, 340, 368, 396

Julian Calendar

Like all leap year types, the one starting with 1 January on a Monday 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 Monday Gregorian calendar Monday