A megasecond (symbol: Ms) 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.
- 1.2096 Ms (14 days) – a fortnight
- 2.3605915 Ms (27.3217 days) – sidereal month
- 2.4192 Ms (28 days) – length of February in non-leap years
- 2.5056 Ms (29 days)– length of February in a leap year
- 2.55144 Ms (29.53059 days) – mean synodic month
- 2.592 Ms (30 days) – length of the months April, June, September, and November
- 2.629746 Ms (30.436875 days) – mean length of a Gregorian calendar month
- 2.6784 Ms (31 days) – length of the months January, March, May, July, August, October, and December
- 7.6 Ms (87 days 23.3 hours) – one orbit of Mercury
- 7.776 Ms (90 days) – approximate length of a quarter year, a common corporate and financial reporting interval
- 8.208 Ms (95 days) - length of Napoleon's attempt at regaining power, known as the Hundred Days
- 8.64 Ms (100 days) - approximate length of the Rwandan genocide
- 19.4141 Ms (224.701 days) — one orbit of Venus
- 22.464 Ms (260 days) — length of the Tzolk'in, or Sacred Round, in the Mayan calendar
- 24.192 Ms (280 days) — average length of a human pregnancy
- 26.2656 Ms (304 days) — length of the year in the calendar of Romulus
- 30.4992, 30.672 or 30.586 Ms (353, 354 or 355 days) — the lengths of regular years in some lunisolar calendars
- 30.6173136 Ms (354.37 days) — 12 lunar months; the average length of a year in lunar calendars
- 31.104 Ms (360 days) — one tun in the Mesoamerican Long Count calendar
- 31.4159265... Ms () — The value of pi times 107 seconds is sometimes given as an approximate year value; it works out to 363.61026 days.
- 31.536 Ms (365 days) — a regular year in many solar calendars. Also the fixed length of the year in the Ancient Egyptian calendar and the length of a Haab in the Mayan calendar.
- 31.556925 Ms (365.24219 days) — a mean tropical year near the year 2000
- 31.556943 Ms (365.2424 days) — a vernal equinox year.
- 31.556952 Ms(365.2425 days) — the average length of a year in the Gregorian calendar
- 31.5576 Ms (365.25 days) — a Julian year, the average length of a year in the Julian calendar
- 31.558153 Ms (365.2564 days) — a sidereal year
Some times beyond this point are too approximate to give values in seconds
- 31.6224 Ms (366 days) — a leap year in many solar calendars; 31.62 million seconds
- 31.622777 Ms (107.5 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
- 729 days — in Canada, 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, otherwise known as "two years less a day"
- 4 years—full term of the President of the United States; (roughly) an Olympiad.
- 4 years, 42 days—duration of World War I
- 4.37 years—the length of time for light from Alpha Centauri to reach Earth
- 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 Australia and the United States. Duration of World War II
- 7 years—the interval between leap seconds on December 31, 1998 and December 31, 2005, the longest one as of 2012[update]
- 10 years—one decade = 3.16 × 108 seconds
- 11 years -- sunspot activity cycle (7.5 to 11 years)
- 11.87 years—one orbit of Jupiter
- 12 years—length of one cycle through the Chinese zodiac (Terrestrial branch)
- 12.27 years—duration of Nazi Germany
- 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 Australia and the United States) one is legally permitted to vote, sign contracts, and to use tobacco products.
- 18.03 years -- Saros cycle, the period of solar eclipses and lunar eclipses
- 19.0002 years—235 months (1 Metonic cycle)
- 19.713 years (7200 days) -- one katun in the Mesoamerican 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
- 29.458 years—one orbit of Saturn
- 30.231 years (11,042 days) —duration of the World Trade Center (time from the completion of the second tower to the towers' destruction on September 11, 2001).