How this calculator works
The Julian year is a defined duration of exactly 365.25 days, each containing 86,400 seconds. It is useful for averaged time intervals but differs from a particular calendar year of 365 or 366 days. The Gregorian calendar average is also slightly different, at 365.2425 days.
Formula
Julian years = days / 365.25; days = Julian years x 365.25.
Worked example
730.5 days is exactly 2 Julian years. Half a Julian year is 182.625 days. A specific two-year calendar interval may contain 730 or 731 days.
Advertisement
Frequently asked questions
Does this calculate age from dates?
No. Age depends on calendar dates and birthdays. This page converts a fixed duration.
Why not divide by 365?
That is a different convention. This page explicitly uses the Julian year of 365.25 days.
Is a leap year one Julian year?
A leap calendar year contains 366 days, slightly more than one 365.25-day Julian year.