Years to Tropical Years (yr to yr (trop))
1 year equals 1.000000849 tropical years (rounded).
How to convert years to tropical years
To convert years to tropical years, multiply the number of years by 1.000000849. The factor is rounded to 10 significant digits. To go the other way, multiply tropical years by 0.9999991512 (rounded).
tropical years = years × 1.000000849
Example: 10 years = 10.00000849 tropical years.
Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.
Approximate value. Standards for the tropical year varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.
About these units
Year (yr)
The average Gregorian calendar year of 365.2425 days (31,556,952 seconds). A common year has 365 days and a leap year 366.
A year is the Earth's trip around the Sun, but there are several versions. The tropical year, which tracks the seasons, is about 365.2422 days. The sidereal year, measured against the stars, is about 365.2564 days, roughly 20 minutes longer, because the Earth's axis precesses. Calendars must squeeze these into whole days, which is the origin of leap years. English year descends from Old English gear, while Latin annus, the source of annual, comes from a different root.
The Gregorian calendar, introduced by Pope Gregory XIII's bull of 24 February 1582, fixed the problem of Julian drift that had moved the March equinox away from 21 March and upset the date of Easter. Ten days were skipped, so Thursday 4 October was followed by Friday 15 October. Its rule of skipping leap days in century years not divisible by 400 gives a mean year of 365.2425 days, the value this site uses for the year. Britain and its empire switched in 1752 and Russia in 1918. Scientists write the year as a, with the Julian year fixed at 31,557,600 seconds.
1 year = 31,556,952 seconds (exactly).
Sources: Wikipedia: Year; Wikipedia: Gregorian calendar
Tropical Year (yr (trop))
About 365.24219 days, the time between successive spring equinoxes. The Gregorian calendar approximates it.
Tropical comes from a Greek word meaning turning, and this year is measured by the cycle of the seasons: the time for the Sun to return to the same ecliptic longitude. The mean value at the start of 2000 was 365.2421897 days, or 365 days 5 hours 48 minutes 45.19 seconds. Individual intervals between March equinoxes wander by minutes, so the mean is what is normally quoted.
Hipparchus timed equinoxes in the second century BC and arrived at 365 days 5 hours 55 minutes 12 seconds, a little long. The Alfonsine Tables of 1252 gave 365 days 5 hours 49 minutes 16 seconds, and this value guided the Gregorian reform of 1582, which was needed because the equinox had slipped about ten days from its date at the Council of Nicaea in 325.
Kepler's Rudolphine Tables of 1627 came within a second or so of the modern figure, and Simon Newcomb's 1898 value of about 365.24219878 days served the national almanacs until 1983. The Gregorian calendar averages 365.2425 days, which tracks the tropical year closely.
1 tropical year = 31,556,925.22 seconds (approximately).
Sources: Wikipedia: Tropical year; NASA Earth Fact Sheet
Related conversions
- Tropical years to years (reverse)
- Years to seconds
- Years to minutes
- Years to hours
- Years to days
- Years to weeks
- Years to months
- Years to milliseconds
- Years to microseconds
- Years to nanoseconds
- Years to decades
- Years to centuries
- Years to millennia
- Seconds to tropical years
- Minutes to tropical years
- Hours to tropical years
- Days to tropical years
- Weeks to tropical years
- Months to tropical years
See all time units.