Megasecond - AbsoluteAstronomy.com

A megasecond is 1 million seconds, or roughly 11.6 days. There are roughly 31.5 megaseconds in a year. This page lists times between 1 and 1000 megaseconds (10⁶ seconds and 10⁹ seconds), or 11.6 days and 31.7 years.

shorter times
Kilosecond
A kilosecond is 1000 seconds , so there are 86.4 kiloseconds in a 24 hour day, and 604.8 kiloseconds in a week. The second is the International System of Units base unit of time, combine with the prefix kilo- which means 1000, results in the definition of a kilosecond...

<1 year

14 days (1.2096 × 10⁶ s) – a fortnight
Fortnight
The fortnight is a unit of time equal to fourteen days, or two weeks. The word derives from the Old English fēowertyne niht, meaning "fourteen nights"....
27.3217 days (2.3605915 × 10⁶ s) – sidereal month
Month
A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept arose with the cycle of moon phases; such months are synodic months and last approximately...
28 days – length of February in non-leap year
Leap year
A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year...

s
29 days – length of February in a leap year
29.53059 days – mean synodic month
30 days (2.592 × 10⁶ s) – length of the months April, June, September, and November
30.436875 days (2.629746 × 10⁶ s) – mean length of a Gregorian calendar month
31 days – length of the months January, March, May, July, August, October, and December
87 days 23.3 hours (7.6 × 10⁶ s) – one orbit of Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
90 days – approximate length of a quarter year, a common corporate and financial reporting interval
95 days - length of Napoleon's attempt at regaining power, known as the Hundred Days
Hundred Days
The Hundred Days, sometimes known as the Hundred Days of Napoleon or Napoleon's Hundred Days for specificity, marked the period between Emperor Napoleon I of France's return from exile on Elba to Paris on 20 March 1815 and the second restoration of King Louis XVIII on 8 July 1815...
100 days - approximate length of the Rwandan genocide
Rwandan Genocide
The Rwandan Genocide was the 1994 mass murder of an estimated 800,000 people in the small East African nation of Rwanda. Over the course of approximately 100 days through mid-July, over 500,000 people were killed, according to a Human Rights Watch estimate...
224.701 days (19.4141 × 10⁶ s) — one orbit of Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
260 days — length of the Tzolk'in
Tzolk'in
Tzolk'in is the name bestowed by Mayanists on the 260-day Mesoamerican calendar used by the Maya civilization of pre-Columbian Mesoamerica.The tzolk'in, the basic cycle of the Maya calendar, is a pre-eminent...

, or Sacred Round, in the Mayan calendar
280 days — average length of a human pregnancy; ~24 million seconds
353, 354 or 355 days — the lengths of regular years in some lunisolar calendar
Lunisolar calendar
A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year then the calendar will...

s
354.37 days (30.6173136 × 10⁶ s) — 12 lunar months; the average length of a year in lunar calendar
Lunar calendar
A lunar calendar is a calendar that is based on cycles of the lunar phase. A common purely lunar calendar is the Islamic calendar or Hijri calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to...

s
— The value of pi times 10⁷ seconds is sometimes given as an approximate year value; it works out to 363.61026 days.
360 days — one tun in the Mesoamerican Long Count calendar
Mesoamerican Long Count calendar
The Mesoamerican Long Count calendar is a non-repeating, vigesimal and base-18 calendar used by several Pre-Columbian Mesoamerican cultures, most notably the Maya. For this reason, it is sometimes known as the Maya Long Count calendar...
365 days — a regular year
Year
A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....

in many solar calendar
Solar calendar
A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun .-Tropical solar calendars:...

s; ~31.53 million seconds. Also the fixed length of the year in the Ancient Egyptian calendar and the length of a Haab in the Mayan calendar.
365.24219 days — a mean tropical year near the year 2000
365.2424 days — a vernal equinox year
Tropical year
A tropical year , for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice...

.
365.2425 days — the average length of a year in the Gregorian calendar
Gregorian calendar
The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...
365.25 days — the average length of a year in the Julian calendar
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
365.2564 days — a sidereal year
Sidereal year
A sidereal year is the time taken by the Earth to orbit the Sun once with respect to the fixed stars. Hence it is also the time taken for the Sun to return to the same position with respect to the fixed stars after apparently travelling once around the ecliptic. It was equal to at noon 1 January...

>1 year

366 days — a leap year
Leap year
A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year...

in many solar calendars; 31.62 million seconds
10^7.5 s — the square root of 10, times 10 million seconds = 31,622,776.6 seconds = 1.00208673 years = 366.004359 days = a leap year plus 6.27 minutes
383.9 days — 13 lunar months; leap year in some lunisolar calendars
383, 384 or 385 days — the lengths of leap years in some lunisolar calendars
686.971 days — one orbit of Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
729 days — in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, the maximum prison sentence that can be served in a provincial correctional facility as opposed to a federal institution under the jurisdiction of the Correctional Service of Canada
Correctional Service of Canada
The Correctional Service of Canada , or CSC, is the Canadian federal government agency responsible for the incarceration and rehabilitation of convicted criminal offenders sentenced to two years or more...

, otherwise known as "two years less a day"
4 years—full term of the President of the United States
President of the United States
The President of the United States of America is the head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces....

; (roughly) an Olympiad
Olympiad
An Olympiad is a period of four years, associated with the Olympic Games of Classical Greece. In the Hellenistic period, beginning with Ephorus, Olympiads were used as calendar epoch....

.
4 years, 42 days—duration of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
4.37 years—the length of time for light from Alpha Centauri
Alpha Centauri
Alpha Centauri is the brightest star in the southern constellation of Centaurus...

to reach Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
4.6 years—orbital period of Ceres
5 years—maximum length of a term in the British and Canadian Parliaments
6 years—full term of a Senator in the United States. Duration of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
7 years—the interval between leap second
Leap second
A leap second is a positive or negative one-second adjustment to the Coordinated Universal Time time scale that keeps it close to mean solar time. UTC, which is used as the basis for official time-of-day radio broadcasts for civil time, is maintained using extremely precise atomic clocks...

s on December 31, 1998 and December 31, 2005, the longest one
10 years—one decade
Decade
A decade is a period of 10 years. The word is derived from the Ancient Greek dekas which means ten. This etymology is sometime confused with the Latin decas and dies , which is not correct....

= 3.16 × 10⁸ seconds
11 years -- sunspot
Sunspot
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....

activity cycle (7.5 to 11 years)
11.87 years—one orbit of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
12 years—length of one cycle through the Chinese zodiac
Chinese zodiac
The Shēngxiào , better known in English as the Chinese Zodiac, is a scheme that relates each year to an animal and its reputed attributes, according to a 12-year mathematical cycle...

(Terrestrial branch)
12.27 years—duration of Nazi Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
13 years—typical time to complete K-12 education in the United States.
15 years—age at which one is first eligible to receive a driver's license in New Zealand.
16 years—usual age at which one is first eligible to receive a driver's license in most States of the United States.
18 years-age at which (in the United States) one is legally permitted to vote, sign contracts, and to use tobacco products.
18.03 years -- Saros cycle
Saros cycle
The saros is a period of 223 synodic months , that can be used to predict eclipses of the Sun and Moon. One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur, in what is referred to as an eclipse cycle...

, the period of solar eclipse
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...

s and lunar eclipse
Lunar eclipse
A lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a...

s
19.0002 years—235 month
Month
A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept arose with the cycle of moon phases; such months are synodic months and last approximately...

s (1 Metonic cycle
Metonic cycle
In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...

)
19.713 years (7200 days) -- one katun
Katun (Maya calendar)
A k'atun or k'atun-cycle is a unit of time in the Maya calendar equal to 20 tuns or 7,200 days, equivalent to 19.713 tropical years. It is the 2nd digit on the normal Maya long count date...

in the Mesoamerican Long Count calendar
Mesoamerican Long Count calendar
The Mesoamerican Long Count calendar is a non-repeating, vigesimal and base-18 calendar used by several Pre-Columbian Mesoamerican cultures, most notably the Maya. For this reason, it is sometimes known as the Maya Long Count calendar...
21 years—age at which one can consume alcoholic beverages in the United States.
29 years—recorded maximum lifespan of a dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
29.458 years—one orbit of Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
30.437 years-duration of the World Trade Center
World Trade Center
The original World Trade Center was a complex with seven buildings featuring landmark twin towers in Lower Manhattan, New York City, United States. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is currently being rebuilt with five new...

Longer times

<1 year

>1 year

See also