April starts on the same day of the week as July in all years, and January in leap years.

In common years no other month starts on the same day of the week as August, though in leap years February starts on the same day.

This may be handled, for example, by adding an extra day in leap years.

Thus it is unperturbed by complications such as leap years.

Their proposals include always observing Easter on the second Sunday in April, or always having seven Sundays between the Epiphany and Ash Wednesday, producing the same result except that in leap years Easter could fall on 7 April.

The days of February 29 of the years AD 100, AD 200, AD 300, and the day created by the irregular application of leap years between the assassination of Caesar and the decree of Augustus re-arranging the calendar in AD 8, remained in effect.

The month has 28 days in common years and 29 days in leap years.

February starts on the same day of the week as March and November in common years, and on the same day of the week as August in leap years.

In leap years, it is the only month that ends on the same weekday it begins.

Under the reforms that instituted the Julian calendar, Intercalaris was abolished, leap years occurred regularly every fourth year, and in leap years February gained a 29th day.

The Gregorian calendar reforms made slight changes to the system for determining which years were leap years and thus contained a 29-day February.

February starts on the same day of the week as both March and November in common years, and August in leap years.

( Years that are evenly divisible by 100 are not leap years, unless they are also evenly divisible by 400, in which case they are leap years.

He must construct transitions so that a dancer who is told to lie prone one second and to leap wildly the next will have some physical preparation for the leap.

Since 30 June 2012 when the last leap second was added, TAI has been exactly 35 seconds ahead of UTC.

This will require the addition of an ever greater number of leap seconds to UTC as long as UTC is kept within one second of UT1.

In this way, decisions made by the original designers of ephemeris time influenced the length of today's standard SI second, and in turn, this has a continuing influence on the number of leap seconds which have been needed for insertion into current broadcast time scales, to keep them approximately in step with mean solar time.

The concepts of the leap year and leap day are distinct from the leap second, which results from changes in the Earth's rotational speed.

In Fear and Trembling, Kierkegaard writes that: "... to be able to fall down in such a way that the same second it looks as if one were standing and walking, to transform the leap of life into a walk, absolutely to express the sublime and the pedestrian -- that only these knights of faith can do -- this is the one and only prodigy.

* 1972 – The first leap second is added to the UTC time system.

In the UTC time scale, a minute on rare occasions has 59 or 61 seconds ; see leap second.

* 1 / 60 minute ( but see also leap second )

* The leap second: its history and possible future

This makes it necessary to insert a leap second at irregular intervals.

* λ and μ Ursae Majoris, Tania Borealis and Australis, the " second leap ";

: This day is similarly added at the end of the second quarter in leap years.

* December 31 – The first leap second since June 30, 1997, occurs.

* June 30 – The International Time Bureau adds the first leap second ( 23: 59: 60 ) to Coordinated Universal Time ( UTC ) at the end of the month.

** An extra leap second ( 23: 59: 60 ) is added to end the year.

As mining developed from simple methods such as panning and sluicing to a new form of commercialized extraction, hydraulic mining, profits from the petering gold rush made a second leap, earning more profits than those miners in the early years had ever made.

By adding a second leap day ( Friday, February 30 ) Sweden reverted to the Julian calendar and the rest of the year ( from Saturday, March 1 ) was in sync with the Julian calendar.

UTC is kept within 0. 9 second of UT1 by the introduction of one-second steps to UTC, the " leap second ".

In solar calendars, this is done by adding to a common year of 365 days, an extra day (" leap day " or " intercalary day ") about every four years, causing a leap year to have 366 days ( Julian, Gregorian and Indian national calendars ).

He set the length of the year to 365. 25 days by adding an intercalary / leap day at the end of February every fourth year.

A leap year ( or intercalary or bissextile year ) is a year containing one additional day ( or, in the case of lunisolar calendars, a month ) in order to keep the calendar year synchronized with the astronomical or seasonal year.

The 1290 days of, ( rather than the 1260 days of ), is thought to be the result of either a simple intercalary leap month adjustment, or due to further calculations related to the prophecy, or due to an intermediate stage of time that is to prepare the world for the beginning of the millennial reign.

It usually has 86, 400 SI seconds per day, but is kept within 0. 9 seconds of UT1 by the introduction of occasional intercalary leap seconds.

In leap years, it is preceded by a 30-day intercalary month named Adar Aleph ( Aleph being the first letter of the Hebrew alphabet ), Adar Rishon ( First Adar ) or Adar I and it is then itself called Adar Bet ( Bet being the second letter of the Hebrew Alphabet ), Adar Sheni ( Second Adar ) or Adar II.

The Coptic calendar has 13 months, 12 of 30 days each and one intercalary month at the end of the year of 5 days in length, except in leap years when the month is 6 days.

Every one of these calendars has a year of 365 days, which is occasionally extended by adding an extra day to form a leap year, a method called " intercalation ", the inserted day being " intercalary ".

Midsummer is also sometimes referred to by Neopagans and others as Litha, stemming from Bede's De temporum ratione which provides Anglo-Saxon names for the months roughly corresponding to June and July as se Ærra Liþa and se Æfterra Liþa ( the " early Litha month " and the " later Litha month ") with an intercalary month of Liþa appearing after se Æfterra Liþa on leap years.

In either case, all other dates have the same dominical letter every year, but the days of the weeks of the dominical letters change within a leap year before and after the intercalary day, 24 February or 29 February.

* Special days and periods ( such as leap day or intercalary day ).

* If the added week is intercalary then people born during a leap week have birthday problems, similar to those born on February 29th.

Mercedonius, also known as Intercalaris, was the intercalary month added in leap years of the Roman calendar.