›› Measurement unit: tropical year

Full name: tropical year

Plural form: years

Symbol: yr

Alternate spelling: tropical years

Category type: time

Scale factor: 31556925.445


›› SI unit: second

The SI base unit for time is the second.
1 second is equal to 3.1688765172731E-8 tropical year.


›› Convert tropical year to another unit

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Valid units must be of the time type.
You can use this form to select from known units:

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›› 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".


›› Sample conversions: tropical year

tropical year to Gregorian month
tropical year to hour
tropical year to Julian month
tropical year to week
tropical year to Julian year
tropical year to anomalistic year
tropical year to day
tropical year to synodic month
tropical year to minute
tropical year to sidereal year