When is the next leap year?
Leap year
The name "leap year" probably comes from the fact that while a fixed date in the Gregorian calendar normally advances one day of the week from one year to the next, the day of the week in the 12 months following the leap day (from March 1 through February 28 of the following year) will advance two days due to the extra day (thus "leaping over" one of the days in the week). For example, Christmas Day (December 25) fell on a Sunday in 2016, and Monday in 2017, then it fell on Tuesday in 2018, and will fall on Wednesday in 2019 but then "leaps" over Thursday to fall on a Friday in 2020.
Leap year
The Hebrew calendar is lunisolar with an embolismic month. This extra month is called "Adar Alef" (first Adar) and is added before "Adar", which then becomes "Adar Bet" (second Adar). According to the Metonic cycle, this is done seven times every nineteen years (specifically, in years 3, 6, 8, 11, 14, 17, and 19). This is to ensure that Passover () is always in the spring as required by the Torah (Pentateuch) in many verses relating to Passover.
Jewish Talmudic Calendar
The position of the years in a Small Mahzor is called the Golden Number. The pattern of the leap years will change slightly each Iggul, but the Jewish Talmudic Calendar fixd the leap years in the year with these golden numbers: 3, 6, 8, 11, 14, 17, 19. If we mark a Leap year as L, the Followship Year as F, and the Other common year as O, we have
Century leap year
In the Gregorian calendar, a year ending in "00" that is divisible by 400 is a century leap year, with the intercalation of February 29 yielding 366 days instead of 365. Century years (divisible by 100) that are "not" divisible by 400 are not leap years but common years of 365 days. For example, the years 1600, 2000, and 2400 are century leap years since those numbers are divisible by 400, while 1700, 1800, 1900, 2100, 2200, and 2300 are common years despite being divisible by 4. Leap years divisible by 400 always start on a Saturday; thus the leap day February 29 in those years always falls on a Tuesday (dominical letter BA).
Perpetual calendar
Within each 100-year block, the cyclic nature of the Gregorian calendar proceeds in exactly the same fashion as its Julian predecessor: A common year begins and ends on the same day of the week, so the following year will begin on the next successive day of the week. A leap year has one more day, so the year following a leap year begins on the "second" day of the week after the leap year began. Every four years, the starting weekday advances five days, so over a 28-year period it advances 35, returning to the same place in both the leap year progression and the starting weekday. This cycle completes three times in 84 years, leaving 16 years in the fourth, incomplete cycle of the century.
Accounting period
The end of the fiscal year would move one day earlier on the calendar each year (two days in leap years) until it would otherwise reach the date four days before the end of the month (August 27 in this case). At that point the first Saturday in the following month (September 3 in this case) becomes the date closest to the end of August and it resets to that date and the fiscal year has 53 weeks instead of 52. In this example the fiscal years ending in 2011 and 2016 have 53 weeks.
Leap second
The UTC standard allows leap seconds to be applied at the end of any UTC month, with first preference to June and December and second preference to March and September. , all of them have been inserted at the end of either June 30 or December 31. IERS publishes announcements every six months, whether leap seconds are to occur or not, in its "Bulletin C". Such announcements are typically published well in advance of each possible leap second date – usually in early January for June 30 and in early July for December 31. Some time signal broadcasts give voice announcements of an impending leap second.
Between 1972 and 2018, a leap second has been inserted about every 20 months, on average. However, the spacing is quite irregular and apparently increasing: there were no leap seconds in the seven-year interval between January 1, 1999 and December 31, 2005, but there were nine leap seconds in the eight years 1972–1979.
Leap year starting on Tuesday
A leap year starting on Tuesday is any year with 366 days (i.e. it includes 29 February) that begins on Tuesday, 1 January, and ends on Wednesday, 31 December. Its dominical letters hence are FE, such as the years 1884, 1924, 1952, 1980, 2008, 2036, 2064, 2092, and 2104 in the Gregorian calendar or, likewise, 1964, 1992, and 2020 in the obsolete Julian calendar. Any leap year that starts on Tuesday, Friday or Saturday has only one Friday the 13th; The only Friday the 13th in this leap year occurs in June. Common years starting on Wednesday share this characteristic.
816
Year 816 (DCCCXVI) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
Common year starting on Monday
A common year starting on Monday is any non-leap year (i.e., a year with 365 days) that begins on Monday, 1 January, and ends on Monday, 31 December. Its dominical letter hence is G. The most recent year of such kind was 2018 and the next one will be 2029 in the Gregorian calendar, or likewise, 2013 and 2019 (the current year) in the obsolete Julian calendar. The century year, 1900, was also a common year starting on Monday in the Gregorian calendar. See below for more. Any common year that starts on Sunday, Monday or Tuesday has two Friday the 13ths. This common year of this type contains two Friday the 13ths in April and July. Leap years starting on Sunday share this characteristic, but also have another in January.
Leap year
A person born on February 29 may be called a "leapling" or a "leaper". In common years, they usually celebrate their birthdays on February 28. In some situations, March 1 is used as the birthday in a non-leap year, since it is the day following February 28.
Tranquility Calendar
The leap year system matches the Gregorian Calendar; thus, the 400-year cycle of leap years starts on 31 AT - every four years is a leap year, except for every hundredth year which is not, except for every four hundredth year which is.
French Republican calendar
and:
These two specifications are incompatible, as leap years defined by the autumnal equinox in Paris do not recur on a regular four-year schedule. Thus, the years III, VII, and XI were observed as leap years, and the years XV and XX were also planned as such, even though they were five years apart.
A fixed arithmetic rule for determining leap years was proposed in the name of the Committee of Public Education by Gilbert Romme on 19 Floréal An III (8 May 1795). The proposed rule was to determine leap years by applying the rules of the Gregorian calendar to the years of the French Republic (years IV, VIII, XII, etc. were to be leap years) except that year 4000 (the last year of ten 400-year periods) should be a common year instead of a leap year. Shortly thereafter, he was sentenced to the guillotine, and his proposal was never adopted and the original astronomical rule continued, which excluded any other fixed arithmetic rule. The proposal was intended to avoid uncertain future leap years caused by the inaccurate astronomical knowledge of the 1790s (even today, this statement is still valid due to the uncertainty in ΔT). In particular, the committee noted that the autumnal equinox of year 144 was predicted to occur at 11:59:40 pm local apparent time in Paris, which was closer to midnight than its inherent 3 to 4 minute uncertainty.
Leap year
The Chinese calendar is lunisolar, so a leap year has an extra month, often called an "embolismic" month after the Greek word for it. In the Chinese calendar the leap month is added according to a rule which ensures that month 11 is always the month that contains the northern winter solstice. The intercalary month takes the same number as the preceding month; for example, if it follows the second month (二月) then it is simply called "leap second month" i.e. .
956
Year 956 (CMLVI) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
1204
Year 1204 (MCCIV) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar.
Leap year
One reason for this rule is that Yom Kippur, the holiest day in the Hebrew calendar and the tenth day of the Hebrew year, now must never be adjacent to the weekly Sabbath (which is Saturday), i.e., it must never fall on Friday or Sunday, in order not to have two adjacent Sabbath days. However, Yom Kippur can still be on Saturday. These rules for the Feasts do not apply to the years from the Creation to the deliverance of the Hebrews from Egypt under Moses. It was at that time (cf. Exodus 13) that the God of Abraham, Isaac and Jacob gave the Hebrews their "Law" including the days to be kept holy and the feast days and Sabbaths.
Leap year starting on Wednesday
Leap years that begin on Wednesday, like those that start on Tuesday, occur at a rate of approximately 14.4% (14 out of 97) of all total leap years in a 400-year cycle of the Gregorian calendar. Their overall occurrence is thus 3.5% (14 out of 400).
ISO week date
For all years, 8 days have a fixed ISO week number (between 01 and 08) in January and February. And with the exception of leap years starting on Thursday, dates with fixed week numbers occur in all months of the year (for 1 day of each ISO week 01 to 52):
During leap years starting on Thursday (i.e. the 13 years numbered 004, 032, 060, 088, 128, 156, 184, 224, 252, 280, 320, 348, 376 in a 400-year cycle), the ISO week numbers are incremented by 1 from March to the rest of the year. This last occurred in 1976 and 2004 and will not occur again before 2032. These exceptions are happening between years that are most often 28 years apart, or 40 years apart for 3 pairs of successive years: from year 088 to 128, from year 184 to 224, and from year 280 to 320.
Leap year
Since 1990 non-retroactively, Hong Kong considers the legal birthday of a leapling March 1 in common years:
Leap year
This rule gives an average year length of 365.25 days. However, it is 11 minutes longer than a tropical year. This means that the vernal equinox moves a day earlier in the calendar about every 131 years.
Old Style leap year starting on Thursday
A leap year is a year with 366 days, as compared to a common year, which has 365.
716
Year 716 (DCCXVI) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. The denomination 716 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Coptic calendar
The following table refers to dates for Coptic years not containing February 29. Such years are preceded by a Coptic leap day at the end of the preceding year. This causes dates to move one day later in the Julian and Gregorian Calendars from the Coptic New Year's Day until the leap day of the Julian or Gregorian Calendar respectively.
Leap year starting on Thursday
A leap year starting on Thursday is any year with 366 days (i.e. it includes 29 February) that begins on Thursday 1 January, and ends on Friday 31 December. Its dominical letters hence are DC, such as the years 1880, 1920, 1948, 1976, 2004, 2032, 2060, and 2088, in the Gregorian calendar or, likewise, 1988, 2016, and 2044 in the obsolete Julian calendar. Any leap year that starts on Monday, Wednesday or Thursday has two Friday the 13ths. This leap year contains two Friday the 13ths in February and August.
Copts
The Coptic year is the extension of the ancient Egyptian civil year, retaining its subdivision into the three seasons, four months each. The three seasons are commemorated by special prayers in the Coptic Liturgy. This calendar is still in use all over Egypt by farmers to keep track of the various agricultural seasons. The Coptic calendar has 13 months, 12 of 30 days each and an intercalary month at the end of the year of 5 or 6 days, depending whether the year is a leap year or not. The year starts on 29 August in the Julian Calendar or on the 30th in the year before (Julian) Leap Years. The Coptic Leap Year follows the same rules as the Julian Calendar so that the extra month always has six days in the year before a Julian Leap Year.
Old Style leap year starting on Tuesday
A leap year is a year with 366 days, as compared to a common year, which has 365.
Century leap year
The Gregorian calendar yields an average year that currently tracks the annual revolution period of the Earth more closely than the older Julian calendar, in which every fourth year (including end-of-century years) is a leap year. The Julian formula adds too many leap days (3 every 400 years), causing the Julian calendar to drift gradually with respect to the astronomical seasons. Over time, natural events such as the spring equinox began to occur earlier and earlier in the Julian calendar.
Old Style leap year starting on Monday
A leap year is a year with 366 days, as compared to a common year, which has 365.
1104
Year 1104 (MCIV) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar.
Leap year
In addition, the Hebrew calendar has postponement rules that postpone the start of the year by one or two days. These postponement rules reduce the number of different combinations of year length and starting days of the week from 28 to 14, and regulate the location of certain religious holidays in relation to the Sabbath. In particular, the first day of the Hebrew year can never be Sunday, Wednesday or Friday. This rule is known in Hebrew as "" (), i.e., "Rosh [ha-Shanah, first day of the year] is not Sunday, Wednesday or Friday" (as the Hebrew word is written by three Hebrew letters signifying Sunday, Wednesday and Friday). Accordingly, the first day of Passover is never Monday, Wednesday or Friday. This rule is known in Hebrew as "" (), which has a double meaning — "Passover is not a legend", but also "Passover is not Monday, Wednesday or Friday" (as the Hebrew word is written by three Hebrew letters signifying Monday, Wednesday and Friday).
Determination of the day of the week
For Julian dates before 1300 and after 1999 the year in the table which differs by an exact multiple of 700 years should be used. For Gregorian dates after 2299, the year in the table which differs by an exact multiple of 400 years should be used. The values "" through "" indicate the remainder when the Hundreds value is divided by 7 and 4 respectively, indicating how the series extend in either direction. Both Julian and Gregorian values are shown 1500–1999 for convenience. Bold figures (e.g., 04) denote leap year. If a year ends in 00 and its hundreds are in bold it is a leap year. Thus 19 indicates that 1900 is not a Gregorian leap year, (but 19 in the Julian column indicates that it "is" a Julian leap year, as are all Julian "x"00 years). 20 indicates that 2000 is a leap year. Use Jan and Feb only in leap years.
Ethiopia
Like the Julian calendar, the sixth epagomenal day—which in essence is a leap day—is added every four years without exception on 29 August of the Julian calendar, six months before the Julian leap day. Thus, the first day of the Ethiopian year, 1 Mäskäräm, for years between 1901 and 2099 (inclusive), is usually 11 September (Gregorian), but falls on 12 September in years before the Gregorian leap year. Also, a seven- to eight-year gap between the Ethiopian and Gregorian calendars results from an alternate calculation in determining the date of the Annunciation of Jesus.
Leap Year (2010 film)
Successful real estate stager Anna Brady (Amy Adams) is frustrated that her cardiologist boyfriend Jeremy Sloane (Adam Scott) still has not proposed to her after four years. She decides to travel from Boston to Dublin, to propose to him on February 29, leap day, while he is there at a conference. Anna wishes to invoke an Irish tradition that a man who is proposed to on leap day must accept the proposal.
4–4–5 calendar
The end of the fiscal year moves one day earlier on the calendar each year (or two days when there is an intervening leap day) until it would otherwise reach the date four days before the end of the month (August 27 in this case) or earlier. At that point the first Saturday in the following month (September 3 or earlier in this case) becomes the date closest to the end of August and it resets to that date and the fiscal year has 53 weeks instead of 52. In this example the fiscal years ending in 2016, 2022, and 2028 have 53 weeks.
Leap year
The Iranian calendar is an observational calendar that starts on the spring equinox and adds a single intercalated day to the last month (Esfand) once every four or five years; the first leap year occurs as the fifth year of the typical 33-year cycle and the remaining leap years occur every four years through the remainder of the 33-year cycle. The system used is more accurate and more complicated, and is based on the time of the March equinox as observed from Tehran. The 33-year period is not completely regular; every so often the 33-year cycle will be broken by a cycle of 29 years.
July 2
This day is the midpoint of a common year because there are 182 days before and 182 days after it in common years, and 183 before and 182 after in leap years. The exact time of the middle of the year is at noon. In countries that use summer time the actual exact time of the midpoint in a common year is at 1:00 p.m, or 11:00 a.m for countries in the southern hemisphere; this is when 182 days and 12 hours have elapsed and there are 182 days and 12 hours remaining. In a leap year in those countries, the midpoint occurs at 1:00 a.m. on July 2, or 11:00pm on July 1 in the southern hemisphere. This is due to summer time having advanced the time by one hour. It falls on the same day of the week as New Year's Day in common years.
840
Year 840 (DCCCXL) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar.
Hanke–Henry Permanent Calendar
The key difference between Robert McClenon's calendar proposal and Henry's modification is that the former has a simple rule for determining which years have a leap week. This rule resembles the Gregorian leap year rule and has the same cycle length. Years whose numbers are divisible by 5 have a leap week, but years whose numbers are divisible by 40 do not have a leap week unless also divisible by 400. The main drawback of this rule is that the new year varies 17 days relative to the Gregorian new year (e.g. year 1965 begins 11 days earlier than Gregorian 1965 and year 2036 begins 6 days later than Gregorian 2036), whereas Henry's rule ensures that the new year always begins within three days of the Gregorian new year.
Determination of the day of the week
Leap years are all years which divide exactly by four with the following exceptions:
Dominical letter
In leap years the formulae above give the Dominical Letter for the last ten months of the year. To find the Dominical Letter for the two first months of the year to the leap day (inclusive) subtract 1 from the calculated number representing the original Dominical Letter; if the new number is less than 0, it must be changed to 6.
Old Style leap year starting on Saturday
A leap year is a year with 366 days, as compared to a common year, which has 365.
24th century
The 24th century of the Anno Domini (common era) will begin on January 1, 2301 and end on December 31, 2400 of the Gregorian calendar. Unlike most century years, the year 2400 will be a leap year, and the next century leap year in the Gregorian calendar after 2000."", "", and "", as well as "Star Trek Generations", "", "", and "" are set in the 24th century.
International Fixed Calendar
Leap year in the International Fixed Calendar contains 366 days, and its occurrence follows the Gregorian rule. There is a leap year in every year whose number is divisible by 4, but not if the year number is divisible by 100, unless it is also divisible by 400. So although the year 2000 was a leap year, the years 1700, 1800, and 1900 were common years. The International Fixed Calendar inserts the extra day in leap year as June 29 - between Saturday June 28 and Sunday Sol 1.
Leap year
if ("year" is not divisible by 4) then (it is a common year)
else if ("year" is not divisible by 100) then (it is a leap year)
else if ("year" is not divisible by 400) then (it is a common year)
else (it is a leap year)The algorithm applies to proleptic Gregorian calendar years before 1, but only if the year is expressed with astronomical year numbering. It is not valid for the BC or BCE notation. The algorithm is not necessarily valid for years in the Julian calendar, such as years before 1752 in the British Empire. The year 1700 was a leap year in the Julian calendar, but not in the Gregorian calendar.
Leap year (disambiguation)
A leap year is a year with an extra day. Leap year may also refer to:
Hanke–Henry Permanent Calendar
The leap rule was chosen to match the ISO week leap rule, to minimise the variation in the start of the year relative to the Gregorian calendar, whereas Robert McClenon originally proposed a simple leap rule which would result in larger astronomic variance: Years whose numbers are divisible by 5 had a leap week, but years whose numbers are divisible by 40 did not unless they are also divisible by 400.
Hebrew calendar
The insertion of the leap month mentioned above is based on the requirement that Passover—the festival celebrating the Exodus from Egypt, which took place in the spring—always occurs in the [northern hemisphere's] spring season. Since the adoption of a fixed calendar, intercalations in the Hebrew calendar have been assigned to fixed points in a 19-year cycle. Prior to this, the intercalation was determined empirically:
Computus
Leap years are all years that divide exactly by four, with the following exceptions:
February
February is also the only month of the calendar that, once every six years and twice every 11 years consecutively, either back into the past or forward into the future, has four full 7-day weeks. In countries that start their week on a Monday, it occurs as part of a common year starting on Friday, in which February 1st is a Monday and the 28th is a Sunday; this occurred in 1965, 1971, 1982, 1993, 1999 and 2010, and occur will again in 2021. In countries that start their week on a Sunday, it occurs in a common year starting on Thursday, with the next occurrence in 2026, and previous occurrences in 1987, 1998, 2009 and 2015. The pattern is broken by a skipped leap year, but no leap year has been skipped since 1900 and no others will be skipped until 2100.
Leap year starting on Sunday
A leap year starting on Sunday is any year with 366 days (i.e. it includes 29 February) that begins on Sunday, 1 January, and ends on Monday, 31 December. Its dominical letters hence are AG, such as the years 1888, 1928, 1956, 1984, 2012, 2040, 2068, 2096, 2108, 2136, 2164, and 2192 in the Gregorian calendar or, likewise, 1996 and 2024 in the obsolete Julian calendar.
Common year starting on Sunday
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). A leap year has two adjoining dominical letters (one for January and February and the other for March to December, as 29 February has no letter). This sequence occurs exactly once within a cycle, and every common letter thrice.
Leap year starting on Wednesday
A leap year starting on Wednesday is any year with 366 days (i.e. it includes 29 February) that begins on Wednesday, 1 January, and ends on Thursday, 31 December. Its dominical letters hence are ED, such as the years 1908, 1936, 1964, 1992, 2020, 2048, 2076, and 2116 in the Gregorian calendar or, likewise, 2004 and 2032 in the obsolete Julian calendar.
Any leap year that starts on Monday, Wednesday or Thursday has two Friday the 13ths. This leap year contains two Friday the 13ths in March and November. Common years starting on Thursday share this characteristic, but also have another in February.
Intercalary month (Egypt)
In the present-day Ethiopian calendar, Paguemain or Pagume is identical to the Coptic intercalary month, beginning on September 6 and ending on September 10 in common years and September 11 in leap years. Its leap years occur at the same time and its dates will also shift forward one day relative to the Gregorian calendar in 2100 (2092).
Leap year starting on Saturday
Leap years that begin on Saturday, along with those that start on Monday or Thursday, occur least frequently: 13 out of 97 (≈ 13.4%) total leap years in a 400-year cycle of the Gregorian calendar. Their overall occurrence is thus 3.25% (13 out of 400).
Doomsday rule
For 29 February falling on a particular weekday, there is just one in every 28 years, and it is of course a leap year.
Leap second
The scheduling of leap seconds was initially delegated to the Bureau International de l'Heure (BIH), but passed to the International Earth Rotation and Reference Systems Service (IERS) on January 1, 1988. IERS usually decides to apply a leap second whenever the difference between UTC and UT1 approaches 0.6 s, in order to keep the difference between UTC and UT1 from exceeding
Coptic calendar
Every fourth Coptic year is a leap year "without exception", as in the Julian calendar, so the above-mentioned new year dates apply only between 1900 and 2099 inclusive in the Gregorian Calendar. In the Julian Calendar, the new year is "always" 29 August, except before a Julian leap year when it is 30 August. Easter is reckoned by the Julian Calendar in the Old Calendarist way.
Leap year starting on Friday
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).
Hebrew calendar
Comparing the days of the week of molad Tishrei with those in the "keviyah" shows that during 39% of years is not postponed beyond the day of the week of its molad Tishrei, 47% are postponed one day, and 14% are postponed two days. This table also identifies the seven types of common years and seven types of leap years. Most are represented in any 19-year cycle, except one or two may be in neighboring cycles. The most likely type of year is 5R7 in 18.1% of years, whereas the least likely is 5C1 in 3.3% of years. The day of the week of is later than that of by one, two or three days for common years and three, four or five days for leap years in deficient, regular or complete years, respectively.
Common year starting on Saturday
A common year starting on Saturday is any non-leap year (i.e. a year with 365 days) that begins on Saturday, 1 January, and ends on Saturday, 31 December. Its dominical letter hence is B. The most recent year of such kind was 2011 and the next one will be 2022 in the Gregorian calendar or, likewise, 2017 and 2023 in the obsolete Julian calendar, see below for more. Any common year that starts on Wednesday, Friday or Saturday has only one Friday the 13th; The only Friday the 13th in this common year occurs in May. Leap years starting on Friday share this characteristic.
Hebrew calendar
The postponement of the year is compensated for by adding a day to the second month or removing one from the third month. A Jewish common year can only have 353, 354, or 355 days. A leap year is always 30 days longer, and so can have 383, 384, or 385 days.Whether a year is deficient, regular, or complete is determined by the time between two adjacent Rosh Hashanah observances and the leap year. While the "keviyah" is sufficient to describe a year, a variant specifies the day of the week for the first day of Pesach (Passover) in lieu of the year length.
Computus
For Julian dates before 1300 and after 1999, the year in the table that differs by an exact multiple of 700 years is used. For Gregorian dates after 2299,the year in the table that differs by an exact multiple of 400 years is used. The values "" through "" indicate the remainder when the Hundreds value is divided by 7 and 4 respectively, indicating how the series extend in either direction. Both Julian and Gregorian values are shown 1500–1999 for convenience. Bold figures (e.g., 04) denote leap year. If a year ends in 00 and its hundreds are in bold it is a leap year. Thus 19 indicates that 1900 is not a Gregorian leap year, (but 19 in the Julian column indicates that it "is" a Julian leap year, as are all Julian "x"00 years). 20 indicates that 2000 is a leap year. Use Jan and Feb only in leap years.
Leap year starting on Tuesday
Leap years that begin on Tuesday, like those that start on Wednesday, occur at a rate of approximately 14.4% of all total leap years in a 400-year cycle of the Gregorian calendar. Their overall occurrence is 3.5% (14 out of 400).
Leap year starting on Sunday
This leap year has the most occurrences of Friday the 13th. Common years starting on Thursday share this feature. Each instance of Friday the 13th is three months apart in January, April, and July.
Leap year starting on Friday
A leap year starting on Friday is any year with 366 days (i.e. it includes 29 February) that begins on Friday 1 January and ends on Saturday 31 December. Its dominical letters hence are CB, such as the years 1904, 1932, 1960, 1988, 2016, 2044, 2072, and 2112 in the Gregorian calendar or, likewise, 2000 and 2028 in the obsolete Julian calendar. Any leap year that starts on Tuesday, Friday or Saturday has only one Friday the 13th; The only Friday the 13th in this leap year occurs in May. Common years starting on Saturday share this characteristic.
1116
Year 1116 (MCXVI) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar.
Leap year
In France, since 1980, a satirical newspaper entitled "La Bougie du Sapeur" is published only on leap year, on February 29.
Wilson Cleveland
Cleveland is the co-creator, executive producer and co-star of "Leap Year", a comedy-drama series about five former co-workers starting a tech company in Silicon Valley, that aired for two seasons on Hulu from 2011 to 2012. It was revealed during the second season that Cleveland's character, Derek Morrison is gay. Cleveland, himself openly gay, explained in a 28 June 2013 "New Media Rockstars" interview, "I wanted Derek’s sexuality to be a subtle layer to the character" and "not make it some big plot twist or its own storyline." In 2013, "Leap Year" won the Webby Award for Best Branded Entertainment (Scripted), the Streamy Award for Best Branded Series and the IAWTV Award for Best Dramatic Series.
856
Year 856 (DCCCLVI) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar.
Common year starting on Wednesday
A common year starting on Wednesday is any non-leap year (i.e. a year with 365 days) that begins on Wednesday, 1 January, and ends on Wednesday, 31 December. Its dominical letter hence is E. The most recent year of such kind was 2014, and the next one will be 2025 in the in the Gregorian calendar or, likewise, 2015 and 2026 in the obsolete Julian calendar. The century year, 1800, was also a common year starting on Wednesday in the Gregorian calendar, see below for more. Any common year that starts on Wednesday, Friday or Saturday has only one Friday the 13th; The only Friday the 13th in this common year occurs in June. Leap years starting on Tuesday share this characteristic.
February 29
February 29, also known as leap day or leap year day, is a date added to most years that are divisible by 4, such as 2012, 2016, 2020, 2024, and 2028. 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 most of the world. Lunisolar calendars (whose months are based on the phases of the Moon) instead add a leap or intercalary month.
Accounting period
The end of the fiscal year would move one day earlier on the calendar each year (two days in leap years) until it would otherwise reach the date seven days before the end of the month (August 24 in this case). At that point it resets to the end of the month (August 31) and the fiscal year has 53 weeks instead of 52. In this example the fiscal years ending in 2008, 2013, and 2019 have 53 weeks.
Dominical letter
A common year is assigned a single dominical letter, indicating which lettered days are Sundays in that particular year (hence the name, from Latin "dominica" for Sunday). Thus, 2017 is A, indicating that all A days are Sunday, and by inference, 1 January 2017 is a Sunday. Leap years are given two letters, the first valid for January 1 – February 28 (or February 24, see below), the second for the remainder of the year.
Dominical letter
Thus a leap year is given two Dominical Letters, as Thurston explains, "the second being the letter which precedes that with which the year started." For example, in 2020 (= ED), all E days preceding the leap day will be Sundays, and all D days for the rest of the year.
Leap year starting on Sunday
Leap years that begin on Sunday, along with those that start on Friday, occur most frequently: 15 out of the 97 (≈ 15.5%) total leap years in a 400-year cycle of the Gregorian calendar. Thus, the overall occurrence is 3.75% (15 out of 400).
Leap year starting on Saturday
Like all leap year types, the one starting with 1 January on a Saturday 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).
Leap year
The observed and calculated versions of the Islamic calendar do not have regular leap days, even though both have lunar months containing 29 or 30 days, generally in alternating order. However, the tabular Islamic calendar used by Islamic astronomers during the Middle Ages and still used by some Muslims does have a regular leap day added to the last month of the lunar year in 11 years of a 30-year cycle. This additional day is found at the end of the last month, Dhu 'l-Hijja, which is also the month of the Hajj.
Tabular Islamic calendar
In its most common form there are 11 leap years in a 30-year cycle. Noting that the average year has 354 11/30 days and a common year has 354 days, at the end of the first year of the 30-year cycle the remainder is 11/30 day. Whenever the remainder exceeds a half day (15/30 day), then a leap day is added to that year, reducing the remainder by one day. Thus at the end of the second year the remainder would be 22/30 day which is reduced to −8/30 day by a leap day. Using this rule the leap years are
of the 30-year cycle. If leap days are added whenever the remainder "equals" or exceeds a half day, then all leap years are the same except 15 replaces 16.
Leap year
In the Hindu calendar, which is a lunisolar calendar, the embolismic month is called "adhika maas" (extra month). It is the month in which the sun is in the same sign of the stellar zodiac on two consecutive dark moons. "Adhika maas" occurs once every 33 to 34 months, compensating for the approximately eleven fewer days per year in twelve lunar months than the solar calendar. Thus, Hindu festivals tend to occur within a given span of the Gregorian calendar. For example: the No Moon during Diwali festival occurs between mid-October and mid-November. Buddhist calendars in several related forms (each a simplified version of the Hindu calendar) are used on mainland Southeast Asia in the countries of Cambodia, Laos, Thailand, Myanmar (formerly Burma) and Sri Lanka.
Leap second
When it occurs, a positive leap second is inserted between second 23:59:59 of a chosen UTC calendar date and second 00:00:00 of the following date. The definition of UTC states that the last day of December and June are preferred, with the last day of March or September as second preference, and the last day of any other month as third preference. All leap seconds (as of 2017) have been scheduled for either June 30 or December 31. The extra second is displayed on UTC clocks as 23:59:60. On clocks that display local time tied to UTC, the leap second may be inserted at the end of some other hour (or half-hour or quarter-hour), depending on the local time zone. A negative leap second would suppress second 23:59:59 of the last day of a chosen month, so that second 23:59:58 of that date would be followed immediately by second 00:00:00 of the following date. Since the introduction of leap seconds, the mean solar day has outpaced UTC only for very brief periods, and has not triggered a negative leap second.
July 1
It is the first day of the second half of the year. The end of this day marks the halfway point of a leap year. It also falls on the same day of the week as New Year's Day in a leap year.
Leap Year (1924 film)
Leap Year is an American silent comedy film directed by and starring Roscoe Arbuckle. Though produced in 1921, the film was not released in the United States due to Arbuckle's involvement in the Virginia Rappe death scandal; it received its first release in Finland in 1924. The film finally saw an American release of sorts in 1981. Prints held by the UCLA Film and Television Archive and Library of Congress."Leap Year" was released on DVD by Laughsmith Entertainment/Mackinac Media on May 24, 2005 as part of the collection titled The Forgotten Films of Roscoe "Fatty" Arbuckle. It was later released on Region 0 DVD-R by Alpha Video on September 1, 2015.
720
Year 720 (DCCXX) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 720 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Dominical letter
Thurston then notes that a complication arises with leap years, which have an extra day. Traditionally, the Catholic ecclesiastical calendar treats 24 February (the "bissextus") as the day added, as this was the Roman leap day ("bis sextus ante Kalendas Martii"), with events normally occurring on 24–28 February moved to 25–29 February. The Anglican and civil calendars treat 29 February as the day added, and do not shift events in this way. But in either case, with leap years, Thurston explains, "1 March is then one day later in the week than 1 February, or, in other words, for the rest of the year [from leap day onward] the Sundays come a day earlier than they would in a common year."
984
Year 984 (CMLXXXIV) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
1416
Year 1416 (MCDXVI) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar.
Leap year
In the Gregorian calendar, the standard calendar in most of the world, most years that are multiples of 4 are leap years. In each leap year, the month of February has 29 days instead of 28. Adding one extra day in the calendar every four years compensates for the fact that a period of 365 days is shorter than a tropical year by almost 6 hours. Some exceptions to this basic rule are required since the duration of a tropical year is slightly less than 365.25 days. The Gregorian reform modified the Julian calendar's scheme of leap years as follows:
Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. For example, the years 1700, 1800, and 1900 are not leap years, but the year 2000 is.
Common year starting on Sunday
A common year starting on Sunday is any non-leap year (i.e. a year with 365 days) that begins on Sunday, 1 January, and ends on Sunday, 31 December. Its dominical letter hence is A. The most recent year of such kind was 2017 and the next one will be 2023 in the Gregorian calendar, or, likewise, 2018 and 2029 in the obsolete Julian calendar, see below for more. Any common year that starts on Sunday, Monday or Tuesday has two Friday the 13ths. This common year contains two Friday the 13ths in January and October.
Leap year
In February 1988 the town of Anthony in Texas, declared itself "leap year capital of the world", and an international leapling birthday club was started.
Common year starting on Friday
In the (currently used) Gregorian calendar, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Friday. The 28-year sub-cycle does only span across century years divisible by 400, e.g. 1600, 2000, and 2400.
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). A leap year has two adjoining dominical letters (one for January and February and the other for March to December, as 29 February has no letter). This sequence occurs exactly once within a cycle, and every common letter thrice.
Leap year starting on Sunday
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 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).
February 29
The Gregorian calendar repeats itself every 400 years, which is exactly 20,871 weeks including 97 leap days (146,097 days). Over this period, February 29 falls on Sunday, Tuesday, and Thursday 13 times each; 14 times each on Friday and Saturday; and 15 times each on Monday and Wednesday. Excepting when a century mark that is not a multiple of 400 intervenes, consecutive leaps days fall in order Thursday, Tuesday, Sunday, Friday, Wednesday, Monday, and Saturday; then repeating with Thursday again.
1040
Year 1040 (MXL) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
Coptic calendar
The Coptic year is the extension of the ancient Egyptian civil year, retaining its subdivision into the three seasons, four months each. The three seasons are commemorated by special prayers in the Coptic Liturgy. This calendar is still in use all over Egypt by farmers to keep track of the various agricultural seasons. The Coptic calendar has 13 months, 12 of 30 days each and one at the end of the year of 5 days in length, except in leap years when the month is 6 days. Today, and until 2099, the year starts on 11 September in the Gregorian Calendar or on the 12th in the year before (Julian) Leap Years. The Coptic Leap Year follows the same rules as the Julian Calendar so that the extra month always has six days in the year before a Julian Leap Year.
Thanksgiving (United States)
The date of Thanksgiving Day follows a 28-year cycle, broken only by century years that are not also a multiple of 400 (2100, 2200, 2300, 2500, …). The cycle break is an effect of the leap year algorithm, which dictates that such years are common years as an adjustment for the calendar-season alignment that leap years provide. Past and future dates of celebration include:
September 11
Between the years AD 1900 and 2099, September 11 of the Gregorian calendar is the leap day of the Coptic and Ethiopian calendars. These leap days occur in the years immediately before leap years in the Julian and Gregorian calendars. In all common years of the Coptic and Ethiopian calendars, September 11 is New Year's Day.
Leap year bug
The leap year bug (also known as the leap year problem) is a problem for both digital (computer-related) and non-digital documentation and data storage situations which results from the wrong calculation of which years are leap years.
Leap year
The Hindu Calendar also known as Vikram Samvat is used in Nepal as the national calendar. All the official work is done based on this calendar.
Old Style leap year starting on Wednesday
A leap year is a year with 366 days, as compared to a common year, which has 365.
Leap Year (2010 film)
The film follows a real estate worker who heads to Ireland to ask her boyfriend to accept her wedding proposal on leap day, when tradition supposedly holds that men cannot refuse a woman's proposal for marriage. Her plans are interrupted by a series of events and are further complicated when she hires an Irish innkeeper to take her to her boyfriend in Dublin.