Unit converter
Days to Julian years.
Convert d to yr and yr to d. Type in either box and the other follows. This uses the Julian year of exactly 365.25 days, the astronomy convention. A calendar year is 365 or 366.
| d | yr |
|---|---|
| 1 d | 0.00273785 yr |
| 7 d | 0.019165 yr |
| 30 d | 0.0821355 yr |
| 90 d | 0.246407 yr |
| 180 d | 0.492813 yr |
| 365 d | 0.999316 yr |
| 500 d | 1.36893 yr |
| 730 d | 1.99863 yr |
| 1000 d | 2.73785 yr |
| 3650 d | 9.99316 yr |
- Conversion goes through s in both directions, so neither figure is rounded on the way.
Definitions
- The day here is exactly 86 400 seconds. Real solar days vary slightly, and leap seconds have occasionally made a calendar day 86 401 s long.
- The year here is the Julian year of exactly 365.25 days, the convention used in astronomy. A calendar year is 365 or 366 days.
- This conversion is exact by definition. 1 d = 0.002737850787 yr.
- Months and years are not fixed durations. The year here is the exact Julian year (365.25 days); the month is a mean Gregorian month, and a calendar month still varies from 28 to 31 days.
How it works
One direction multiplies and the other divides by the same number, so nothing is lost by going back and forth.
The value passes through s, the unit every other time unit on the site is defined against, rather than a number written into this page on its own. That is why the figure here, the figure in the table above and the general time converter always agree.
Display precision limits significant figures rather than decimal places, because one fixed number of decimals is useless across a range this wide. Very large and very small results switch to scientific notation with a proper superscript exponent. The editable box always holds a plain number at full working precision, so you can carry on from either side.
Common questions this answers: how many Julian years in a day (0.00273785), how many days in a year (julian, 365.25 d) (365.25), and what 365 d is in Julian years (0.999316 yr).
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