## ››Convert second to tropical year

 seconds tropical year

How many seconds in 1 tropical year? The answer is 31556925.445.
We assume you are converting between second and tropical year.
You can view more details on each measurement unit:
seconds or tropical year
The SI base unit for time is the second.
1 second is equal to 3.1688765172731E-8 tropical year.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between seconds and years.
Type in your own numbers in the form to convert the units!

## ››Date difference between calendar days

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You can do the reverse unit conversion from tropical year to seconds, or enter any two units below:

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## ››Definition: Second

The second (symbol s) is a unit for time, and one of seven SI base units. It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at zero kelvins.

## ››Definition: Year

The mean tropical year is defined as the period of time for the mean ecliptic longitude of the Sun to increase by 360 degrees. Since the Sun's ecliptic longitude is measured with respect to the equinox, the tropical year comprises a complete cycle of the seasons; because of the biological and socio-economic importance of the seasons, the tropical year is the basis of most calendars.

The International Union of Pure and Applied Chemistry and the International Union of Geological Sciences have jointly recommended using defining the annus, with symbol a, as the length of the tropical year in the year 2000:

a = 31556925.445 seconds (approximately 365.24219265 ephemeris days)

We default to using the Gregorian year on this site, but you can select a specific type of year by entering the full name like "tropical year".

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ConvertUnits.com provides an online conversion calculator for all types of measurement units. You can find metric conversion tables for SI units, as well as English units, currency, and other data. Type in unit symbols, abbreviations, or full names for units of length, area, mass, pressure, and other types. Examples include mm, inch, 100 kg, US fluid ounce, 6'3", 10 stone 4, cubic cm, metres squared, grams, moles, feet per second, and many more!